Page 1 of 2 12 LastLast
Results 1 to 50 of 54

Thread: alternative to epoxy for fairing?

  1. #1

    Default alternative to epoxy for fairing?

    in my previous post i talked about my poor tape job, actually its not as bad as i thought. i am however completely DONE using epoxy for ANYTHING! i have mixed about 12-13 batches of epoxy/cabosil/microballons and i find it terrible for fairing, no combination of ratio works well. if it goes on well it sags, if it doesnt sag it goes on like damp sawdust. can i use marine "bondo"? what about polyester resin/talc? i have painted a couple of cars and a dozen or more motorcycles so getting a fair surface isnt new to me. if i cant find a different product my current alternative is a bon fire. thanks.
    Last edited by rodjr; 06-05-2011 at 07:20 PM.

  2. #2
    Join Date
    Jul 2005
    Location
    Oklahoma
    Posts
    19

    Default Re: alternative to epoxy for fairing?

    You might try it without the Cabosil. I use epoxy with phenolic microballoons and it works fine for me.

  3. #3
    Join Date
    Dec 2003
    Location
    on-the-cuyahoga
    Posts
    13,017

    Default Re: alternative to epoxy for fairing?

    All thickeners are not the same. There are fibers like chopped cotten, chopped glass and wood flour for strength. Fumed silica (Cabosil among others) for hardness and microballoons for ease of sanding.

  4. #4
    Join Date
    Dec 2008
    Location
    Bay Area, Northern California
    Posts
    618

    Default Re: alternative to epoxy for fairing?

    R, A little exitable perhaps! Epoxy, while sticky and toxic,is not the devil... ( dont eat it, or rub it on your chest...)
    If you do want to make fairing compound with your resin, you want to use microballoons, mixing in the red( or sometimes white) ultra light powder until you arrive at the perfect mix that will spread but still hang( it can take a while). It can be done. I, in recent years, have taken to buying epoxy fairing compound, a two part mix that, well mixed, will yeald a beutiful smooth fairing compound. The brand I can find locally is Silver Tip Quick Fair, I believe it is System Three brand. In any case, the key is to 'keep you head , when all about you are losing theirs'... wishing you well, BT

  5. #5

    Default Re: alternative to epoxy for fairing?

    i dont doubt it can be done, many seem to do it. epoxy is not for me, i find the stuff exhausting in every way. im not impressed with it. now the brown resin glue works great. i intend to build more boats in the future (i have several sets of plans) but epoxy is out. will polyester resin work over epoxy? on future boats i will use the polyester through and through. i have used it before and find it much more freindly, so i would like to switch now.

  6. #6
    Join Date
    Oct 2009
    Location
    South Puget Sound/summer Eastern carib./winter
    Posts
    8,746

    Default Re: alternative to epoxy for fairing?

    You have used epoxy incorrectly by using the wrong filler.

    west 407 is for fairing (red) . sands easily
    west 410 is for ultra fairing(beige). sands VERY easily, only recommended for very thin application.


    If you glue stuff with fairing fillers, it will break. If you try to fair with gluing fillers,well, that you now know .

  7. #7

    Default Re: alternative to epoxy for fairing?

    i am using microballons for fairing, is this incorrect? i tried a couple batches where i added very small amounts of cabosil as suggested in another thread.

  8. #8
    Join Date
    Nov 2008
    Location
    Warnbro, Western Australia
    Posts
    169

    Default Re: alternative to epoxy for fairing?

    Sounds like you haven't been having much fun here rodjr, I wonder if you might not benefit from sitting down with someone more familiar with epoxy and look at how you're working. Epoxy really is far superior to polyester in so many ways, from not smelling as badly through being stronger, more flexible, with better adhesion, better water resistance and on and on. There's many reasons why epoxy has replaced polyester in boat building.

    For fairing, I use micro balloons which are microscopic balls. Being balls they don't hold within the epoxy as well as micro fibers or wood flour which have jagged edges and also absorb the resin. Micro balloons therefore sand much easier and give a really nice smooth finish at the expense of requiring a much thicker mix to start with - the very thing which makes them easy to sand also makes the goop slump much more so you need to mix it up more like an icing sugar than peanut butter consistency.

    Polyster on the other hand doesn't adhere anywhere near as well and has a greater shrinkage than epoxy - up to 7%- and takes much longer to cure. You run the risk of having your lovely fairing work shrink away from the surface a few weeks after you thought you had finished. It's far more likely to blister from water absorption as well. In short .... horrible stuff.

    Honestly rodjr, stick with it, watch others using it and figure out what it is they do which you're not. It sure isn't as nice to work with as honest timber and clever carpentry, but it leaves polyester in the shade.

  9. #9
    Join Date
    Jun 2000
    Location
    Madison Wisconsin
    Posts
    6,812

    Default Re: alternative to epoxy for fairing?

    Yep, your "problems" with epoxy are completely due to not being familiar with the products and how to combine/use them. I don't know about you, but most of us weren't born with the knowledge of how to use epoxy systems correctly and to do so took some studying. You can do what you want, but if you want to be serious about building wood/composite boats, some time with your nose burried in a couple of good books on epoxy boat work (The Gougeon Brothers on Boat Construction is the best) would be well worth your time. Since polyester doesn't seal wood well, or in most cases even stick to wood well, you can pretty much bet that it will probably fail and not be worth wasting your time or money on. You could always swear-off composite building and go traditional, old style, but complaining about and blaming the epoxy when you haven't yet learned how to use it, and claiming you're switching to polyester isn't very bright and certainly isn't a formula for success.

  10. #10
    Join Date
    Mar 2007
    Location
    East Quogue,NY
    Posts
    6,069

    Default Re: alternative to epoxy for fairing?

    +1 on try, try again. You'll get it. I might add that part of the art of this lies in the mix of fillers; another part lies in the cure rate. In my experience, epoxy mixtures get thinnner a few minutes intp cure, than start to tighten up. So there is a "sweet spot" in both mix AND when to start filetng after mixing. ( and when to quit if the batch your using gets too stiff/too far into cure.

    My Two Cents

    Kevin
    There are two kinds of boaters: those who have run aground, and those who lie about it.

  11. #11
    Join Date
    Dec 2007
    Location
    California Delta
    Posts
    1,328

    Default Re: alternative to epoxy for fairing?

    rodjr: if your final surface is to be painted why not use Interlux Surfacing Putty on bare wood? It feathters out just like automotive bondo. Jeez, all this epoxy crap for above waterline use drives me nuts. It's expensive hocus pocus that make no sense.
    "Whiskey is for drinking, water is for fighting over." -Samuel Clemens

  12. #12
    Join Date
    Feb 2010
    Location
    Seattle, WA
    Posts
    765

    Default Re: alternative to epoxy for fairing?

    Ditto that. Evercoat or a good High build primer can cover a lot of sins.

  13. #13
    Join Date
    Dec 2009
    Location
    Cape Ann
    Posts
    49

    Default Re: alternative to epoxy for fairing?

    If you don't have good luck mixing your own, I would recommend a pre mixed epoxy fairing compound. Interlux makes one (or did) for above or below the waterline. It was the perfect consistency, didn't sag, went on very smooth. Good Luck.

  14. #14
    Join Date
    Apr 2005
    Posts
    221

    Default Re: alternative to epoxy for fairing?

    +1 on the pre mixed epoxy fairing compound. Having mixed my own for years I will now not bother as the pre mixed is far nicer to use.

  15. #15
    Join Date
    May 2005
    Location
    Edmond, OK
    Posts
    841

    Default Re: alternative to epoxy for fairing?

    Quickfair. IMHO, this product is optimal for your task.


  16. #16
    Join Date
    Apr 2011
    Location
    St-Hippolyte, Qc
    Posts
    1,012

    Default Re: alternative to epoxy for fairing?

    I am not a epoxy fan either, actually I avoid it everywhere I can. I have a really bad skin reaction when using it also...

    Polyester don't stick on top of epoxy, once you started with epoxy you have to go all the way with it. For wood you can use Resorcinol as a alternative to epoxy, lot less toxic to work with and clean with water when not cure which is handy to clean tools, gloves etc...but require a tight fit and heat to cure (Electric blanket).

    You've started with epoxy, so you got to finish it with it.
    http://www.peacefuljourney.ca/
    BEWARE: I am a native french speaker

  17. #17
    Join Date
    Nov 2009
    Location
    Coastal NC
    Posts
    87

    Default Re: alternative to epoxy for fairing?

    I would add that smaller batches of epoxy/microballons were key for me. Larger batches hold heat and kick off quicker. I mix a small amount of epoxy, quickly add filler, and transfer to a plastic board and spread it out to help cool it and slow curing. I have also used a piece of sheet metal as a palette. Your mileage may vary...

    JHP

  18. #18
    Join Date
    Oct 2000
    Location
    Wellesley, MA USA
    Posts
    8,813

    Default Re: alternative to epoxy for fairing?

    Because the bubbles are good insulators, the heat of epoxy curing is retained and a mass of bog can cure more quickly than you want. Because of this, I generally use slow hardener and with large batches a plasterer's hawk will help dissipate heat.

  19. #19
    Join Date
    Nov 2008
    Location
    Huntington, NY
    Posts
    1,102

    Default Re: alternative to epoxy for fairing?

    Quote Originally Posted by yzer View Post
    rodjr: if your final surface is to be painted why not use Interlux Surfacing Putty on bare wood? It feathters out just like automotive bondo. Jeez, all this epoxy crap for above waterline use drives me nuts. It's expensive hocus pocus that make no sense.
    Or how about just sanding so the surface doesn't need to be faired? I must be missing something.
    -- John

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Check out my blog: http://www.unlikelyboatbuilder.com
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    "What people say you cannot do, you try and find you can." -- Thoreau

  20. #20
    Join Date
    Jul 2009
    Location
    Dearborn, Michigan
    Posts
    244

    Default Re: alternative to epoxy for fairing?

    I feel your pain. I experienced the same thing a couple of summers ago. My problem was the result of trying to fair over 12 ounce biaxial fabric, which is way overkill for my small boat.

    My advice: Mix in small batches, wash off the amine blush between coats or the new ones will not stick. To prevent sag, I rotated the hull so it was not so vertical. That helped the most. The goal is to avoid sanding as much as possible. The right mixture of microballoons and cabosil will take time and experimentation.

    That Quick Fair looks very promising.

    Hang in there; don't give up. Polyester is not an option.

  21. #21
    Join Date
    Apr 2003
    Location
    Dallas and points north
    Posts
    5,862

    Default Re: alternative to epoxy for fairing?

    I too was wondering how much of the hull you actually need to fair... usually fairing is applied areas where you could not sand the underlying material smoothly.

    Epoxy is not difficult to work with at all... but there is a learning curve and you have to expend some effort in getting the "feel" of the product... and towards working with common sense organization in your work flow and "working clean". Some good advice above...but perhaps its best to think back when we all started and remember the small details left out that caused us all to make a few mistakes and learn some hard way.

    This may make it clear to you... when you first start working with epoxy, you tend to mix smaller batches and use medium or slow hardener to give you time to make the application... but... as you progress in product knowledge and application techniques and skill, you will tend to use fast hardener most of the time because it just goes off faster and saves you tons of time and most important of all, you have developed your skill in epoxy application to the point that you do not need much time to achieve a quality application. Naturally, this depends on the job you are doing because some applications require slow hardener or medium because the task required takes a bit of time.

    For fairing I use a mixture of half cabosil, and about 40% talc, and 10% wood flour. I mix to the consistency close to peanut butter. I use talc because unlike microbaloons, when sanded you get a nice smooth finish... whereas micro-baloons get sanded in half... and need to be coated with epoxy to fill the voids. Don't be afraid to do some testing with mixtures and be consistent and keep track of exactly how you mixed the test compound. With experience, you will learn to just apply the cabosil and the other thickeners till you get the feel you want of the fairing compound. Cabosil is required because of its thixotrophic nature, which is necessary to keep the epoxy from sagging. Many times I use cabosil and talc about even in ratio.... but usually mix a bit more talc (Johnsons Baby Powder that says talc is main ingredient) because it makes for easier sanding.

    Probably, the best advice above other than taking time to learn about epoxy in general.... is to buy the pre-mixed mentioned above from System Three. It costs more than you mixing your own, and you can take your time learning to mix your own over time. Sometimes the time saved with pre-mixed products is money well spent.

    Get the System Three Epoxy Manual (free pdf online) and "The Gougeon Brothers on Boat Construction"... and try to lose the negative attititude towards epoxy. Epoxy makes things possible that you cannot imagine once you learn all of it's abilities and how to use it. Find someone who you can use as a mentor in these initial stages so that you can make a call and save the time and wasted efforts from a simple mistake. You can always ask here on the forum or pm some of the more knowledgable guys.

    One more thing, when fairing use a smooth 6" squeege and/or a 4" or 6" metal putty knife and constantly keep it clean with an old disposable rag so that each time you make a stroke with the squeege or knife, you get a perfectly smooth surface. If you fail to wipe off the contact surface of your fairing tool, you will have problems getting a nice fair result. Remember, epoxy is not all that easy to sand so when you are fairing you try to get as smooth a finish as reasonable when using the fairing tools.... then sanding will be minimized.

    Good luck,

    RodB
    Last edited by RodB; 06-06-2011 at 03:48 PM.

  22. #22
    Join Date
    Nov 2008
    Location
    Huntington, NY
    Posts
    1,102

    Default Re: alternative to epoxy for fairing?

    Quote Originally Posted by jalmberg View Post
    Or how about just sanding so the surface doesn't need to be faired? I must be missing something.
    Oh... found the previous thread. One thing a newbie should try to do is to make mistakes slowly. Sounds like the main tool needed for this project is patience.
    -- John

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Check out my blog: http://www.unlikelyboatbuilder.com
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    "What people say you cannot do, you try and find you can." -- Thoreau

  23. #23
    Join Date
    Jul 2007
    Location
    Sturgis MI
    Posts
    536

    Default Re: alternative to epoxy for fairing?

    I find that I have the best result using straight red balloons and using several very thin coats rather than trying to put on much at once. If I put it on too thick then it sags.
    I ended up using four or five coats to do what i would have done in one pass using bondo on a car body.


    i feel your fairing pain,

    Jerry

  24. #24
    Join Date
    Jun 2000
    Location
    Madison Wisconsin
    Posts
    6,812

    Default Re: alternative to epoxy for fairing?

    If it sags, you need more filler in it. The mixture of resin to balloons for good fairing compound has a little bit of resin and a rather large pile of balloons. Make a test sample, mix it up, stick some on a board and let it sit there for half an hour. If it sags at all, you need more filler and you want to keep track of the amount you're adding so that you can duplicate that proper mix once you find it with your tests. As with any highly-filled resin mixture (home-brewed or commercial) you also want to pre-coat the wood with plain resin/hardener first, because high amounts of most fillers reduce the adhesive qualities of the resin mixture. Usually, this can be done just minutes before you start filling. Mix a bit more resin and hardener than you need, give the area a quick, thin coat and them mix your filler in and start filling. There is nothing mysterious about it.

  25. #25
    Join Date
    Oct 2000
    Location
    Wellesley, MA USA
    Posts
    8,813

    Default Re: alternative to epoxy for fairing?

    When I have a significant depth to fill (1/8" or more) over more than a square foot, I'll apply the bog with a notched spreader. There are plastic notched spreaders at the big box for applying flooring mastic and West System has some nice little plastic spreaders that are about 4" square. The notched spreaders offer better control of depth than a flat spreader and lay down half as much material for a given depth. When the notched spreader bog has cured, sand the ridges to the desired contour with a longboard or an appropriately large block and coarse paper. Because you only have 50% coverage, the sanding will be quite easy. It'll look like noodles on the surface. Get the loose dust out with a vac or airhose, then with a smooth spreader or drywall knife, spread bog into the grooves between the noodles.
    This method save a lot of material and a lot of effort and is applicable to Quickfair or 'mother's recipe" bog.

    I prefer quartz microspheres to phenolic microballoons, mostly because they're half the price. A 5 gallon bucket is about $40. When I think of it a little cabosil makes the bog smoother and less apt to slump.
    Last edited by JimConlin; 06-06-2011 at 08:22 PM.

  26. #26

    Default Re: alternative to epoxy for fairing?

    at this point i have about 90hrs and $160 worth of epoxy supply's invested in fairing the inside only of a 9' boat. i spent 11hrs on it today and my luck has not turned. im going to grind out all the tape, most of the fillet material, then redo the fillets much fatter. then ill cut my own tape from 4 oz cloth and do 2 layers, one wider than the first to blend better than 1 layer of the premade 6oz tape. then i think ill just use multiple coats of unthickened epoxy to build up, and sand it all in. im sure all of that will be less trouble than finishing it this way. or it may even be just as easy to cut out a strongback, frames, etc, and glue, screw and nail together a conventional construction boat. thank you for all the suggestions, i assure you i tried many today.

  27. #27
    Join Date
    Oct 2009
    Location
    South Puget Sound/summer Eastern carib./winter
    Posts
    8,746

    Default Re: alternative to epoxy for fairing?

    Your hours and money spent do not reflect accurately on how well epoxy can work. For twice the money and half the time I built this.

  28. #28
    Join Date
    Apr 2011
    Location
    St-Hippolyte, Qc
    Posts
    1,012

    Default Re: alternative to epoxy for fairing?

    @wizband it look like a big shoe, where is the other one?
    http://www.peacefuljourney.ca/
    BEWARE: I am a native french speaker

  29. #29
    Join Date
    Dec 2008
    Location
    Bay Area, Northern California
    Posts
    618

    Default Re: alternative to epoxy for fairing?

    Rod, Hate to see you bouncing all over the place, swearing off this or that material...Slow down, relax, it will be OK, this is not, as they say a piano...I encourage you to do whatever seems best to you, but your last post sounds like you are lining yourself up for more hard times, first, taking the tape out will not be an easy feat,you will likely be taking out some of your plywood with it...second, while two tapes are fine, cutting your own tapes, in my experience leads to tough layups, I much prefer to work with premade tapes ( say a 3" and a 5") as the selvage edge doesn't unravel, leading to threads pulling out helter-skelter as you are laminating, I can already see the veins poking out of yer neck from here!
    A reasonably workman like tape job will look just fine with no fairing at all under a coat or two of paint. wishing you well, Cheers, BT

  30. #30

    Default Re: alternative to epoxy for fairing?

    unfortunately at this point most of the original tape is very, very thin from all the sanding/filling disasters so more tape will be needed to hold the boat together anyway. doesnt seam a good idea to put another layer over an unfair microballon/ thin tape joint. so repairs are needed to move on.

  31. #31
    Join Date
    Oct 2009
    Location
    South Puget Sound/summer Eastern carib./winter
    Posts
    8,746

    Default Re: alternative to epoxy for fairing?

    What are you building rodgr,( excuse me for not knowing). My 40mph" shoe" has no tape. Filets only. It lands /works harder than any rowboat and most sailboats.

  32. #32

    Default Re: alternative to epoxy for fairing?

    the project in progress is a selway fisher stornoway 9, 11 planks total so lots of seams. some of the seams are nearly flat so the fillets are just large enough to let me get the wire out before i taped. im trying to get a new attitude, so today im just using the boat as a sacrificial lamb. ill keep trying on a few seams until i get it, when im certain i can produce the results im looking for ill start a new boat. ill keep this one around and if i run into trouble in another area, ill practice on the "test mule" instead of killing a good project.

  33. #33
    Join Date
    Dec 2001
    Location
    Fiddletown, on Vineyard Lane
    Posts
    2,443

    Default Re: alternative to epoxy for fairing?

    Going forward (I am inferring that you are facing further work with epoxy), use automotive tape and paper to mask areas that you are epoxying, and remove those items while the pox is wet. If you don't, you'll have a second set of problems getting tape and paper off, which will also mar the wood (two problems for every solution, as my uncle used to say). I have found that careful prep before application goes miles over trying to finish and fair after the fact. I too am an amateur poor at fairing, though at this stage it is aggravation and not unfamiliarity with the process. I get focused on my next build and then half-ass the finish work. I am nearing finishing stage of a Coquina and I am going to have to really confront these issues myself, or wind up with a workboat finish on a masterpiece design. You've got some advice here from some guys doing brilliant work though!
    Last edited by davebrown; 06-09-2011 at 11:43 PM.

  34. #34
    Join Date
    Apr 2003
    Location
    Dallas and points north
    Posts
    5,862

    Default Re: alternative to epoxy for fairing?


  35. #35
    Join Date
    May 2000
    Location
    Cummington
    Posts
    4,409

    Default Re: alternative to epoxy for fairing?

    I'd avoided this thread but took a look -- so I guess the answer to your question is "no", as none has been suggested

  36. #36

    Default Re: alternative to epoxy for fairing?

    If you hate epoxy, don't use it for future boats. . . slathering plywood in toxic waste is not the only way to build a "wooden" boat.

    Your hatred of it is a correct instinct that will lead you in cleaner and more interesting directions, ie building in solid wood.

  37. #37

    Default Re: alternative to epoxy for fairing?

    well i spent $2.99 on some baby powder (talc and fragrance only) and WOW! i mixed 3 oz epoxy, about 10% cabosil, 40% talc, 50% balloons and its amazing! smooth, WILL NOT sag, finds the low spot every time, and seems to stretch twice as far. sands almost as good as spackle. im still going to avoid epoxy on future projects for any use besides adhesive, no more tape either. but for now baby powder has saved my butt. many thanks to all who have tolerated my ranting, and offered help.

  38. #38
    Join Date
    Oct 2009
    Location
    South Puget Sound/summer Eastern carib./winter
    Posts
    8,746

    Default Re: alternative to epoxy for fairing?

    "its amazing!" , Yup, as Bugs Bunny sez "yer gettin warma"

  39. #39
    Join Date
    Apr 2003
    Location
    Dallas and points north
    Posts
    5,862

    Default Re: alternative to epoxy for fairing?

    rodjr,

    You obviously made up a very thick mixture for fairing... but I wonder how it would work on a vertical surface without sagging if wet enough to form a good bond. Of course you can thicken epoxy to a very thick consistency and it will not sag much but will also not be very wet and form a really solid bond to the surrounding surface. ... or as strong as it could be.

    The talc is much heavier than the rest of the fillers you used... so it settles to the bottom of a void easily... but if you need the fairing compound to not sag... especially on vertical surfaces... you need to keep the cabosil to close to 50% of the fillers.

    Cabosil is what makes the epoxy thickened mixture smooth and not SAG.... it is the thixotrophic filler here. IF you want the completed fairing job to be easily sanded and not require another coat of epoxy to be applied to fill the voids in the sanded microbaloons, then you should not use microbaloons. Try thickening with a mixture of 50% cabosil, 30% talc and 20% wood flour... I think you'll be satisfied with this mixture. Be sure to get the epoxy thickened to almost a peanut butter consistency.... Play with this mixture some ( you will figure out the right consistency PDQ) and see the difference on vertical surfaces where gravity has the max effect... and on horizontal surfaces where you just want a void filled and sagging is less of a factor. I also use a 50:50 mixture of talc and cabosil on fairing jobs with smaller voids etc...and tend to mix a slight bit wetter to achieve very smooth coverage of these areas ... and later sanding is a breeze.


    Use a clean putty knife or squeege... and keep wiping the tools blade off with a paper towel or rag so that you are always working with a clean surface on the tool. This is very important if you are fairing a larger surface for example say a 2" by 8 inch long area along the edge of biaxial tape for example. Apply epoxy along the area to be faired.. then use a clean 3" wide putty knife blade to smooth it over with one stroke... if done right, you have very little sanding to do later. This is assuming you have already sanded off the high points of the biaxial tape.

    There is not one way to do anything in this epoxy boatbuilding work... so don't be afraid to experiment with the filler mxture... but keep in mind that there are some basic tenants you need to follow to avoid wasting lots of hours. Don't be afraid of asking before you act... sometimes a simple question saves you tons of time later on undoing a mistake.

    Good luck.

    R


    FROM SYSTEM THREE EPOXY MANUAL:
    For those who choose to homebrew putties we offer the follow- ing: Our general purpose epoxy can be mixed with phenolic mi- croballoons (purple), quartz microspheres (white), or wood flour (brown) to make a putty-like material that is used for making cos- metic or structural filleting, fairing, or molding compounds. The use of these materials with the right portions of silica thickener makes a smoother compound than the fillers alone can produce. The amount of these fillers is best determined by experimentation taking into account the desired results, temperature and viscosity of the epoxy being used.... .... Microballoons and microspheres do thicken the epoxy, but when used in proper loadings do not prevent sagging, and need the addition of a thixotropic agent like silica thickener

    http://www.systemthree.com/reslibrar...Epoxy_Book.pdf

    http://www.systemthree.com/reslibrar...literature.asp
    Last edited by RodB; 06-09-2011 at 04:47 PM.

  40. #40
    Join Date
    Apr 2011
    Location
    St-Hippolyte, Qc
    Posts
    1,012

    Default Re: alternative to epoxy for fairing?

    When we gonna see the pictures? To see if it's that bad or you just a perfectionist
    I have build a selway dingy also... I favor stitch and glue for dingy (Specially cruising one) cause they have a hard life, bashing again't a pilling, going along a concrete wall, drag it on a rocky beach, throwing chain it in for another anchor etc...

    This way it's easy to patch for repair...
    It's the Redshank, a bit similar to yours... but with 8 planks per side, she can be build with 6 but 8 look better. So 16 in total for a smaller size...
    Ok the finishing (Varnish and paint) was not done on the pictures... I am still working on it, as the big boat take all my time.


    Last edited by JoshuaIII; 06-10-2011 at 08:27 AM.
    http://www.peacefuljourney.ca/
    BEWARE: I am a native french speaker

  41. #41
    Join Date
    May 2004
    Location
    Cuyahoga Falls, Ohio
    Posts
    2,699

    Default Re: alternative to epoxy for fairing?

    Geez, this is the third one of these in about a week or so.
    Where to start....
    Fairing with unthickened epoxy is a fools errand. Way too much work.
    Polyester on a wood boat as stated above doesn't work well enough to be worth your time.
    Cutting your own tape is a nightmare.
    There are NO shortcuts. Read the literature. Work out the learning curve on scraps. Get a moaning chair. Everyone screws up now and then - walk away from it until you settle down. Your work on cars probably wasn't first rate at the beginning either.
    Finding a local builder who will mentor you would be a treasure.
    Best of luck,
    Tom

  42. #42

    Default Re: alternative to epoxy for fairing?

    rolled the boat today and 4 of 11 scarfs failed. boat has been destroyed. all epoxy supplys, 3 sets of stitch and glue plans for sale. already started cutting hartley husky 9'3" ply on frames. god i love resin glue, and working with wood! actually my attitude is good (for a guy who just destroyed 160hrs work and $500.00 plus.), stitch and glue just isnt my thing.

  43. #43
    Join Date
    Apr 2003
    Location
    Dallas and points north
    Posts
    5,862

    Default Re: alternative to epoxy for fairing?

    Patience doesn't mean only with the building process... it takes patience to do homework before beginning a project. Epoxy construction has basic tenants that must be followed... or many problems arise...

    I'm sorry for your negative experience, I wish you had a mentor before starting this project...

    Fair Winds...

    RodB

  44. #44
    Join Date
    Apr 2011
    Location
    St-Hippolyte, Qc
    Posts
    1,012

    Default Re: alternative to epoxy for fairing?

    There is 2 kind of person... The guy that have experience with wood and love joinery and fit perfectly wood and the other...
    For the other epoxy and stitch and glue is great, but when you are use to do nice joinery, and now you can't because epoxy need a gap, fillet hide all joinery, and sanding fiberglass dust came to life it is not fun.

    I hate stitch and glue because I can't do nice joinery on it, and I understand why you don't like it. But it is not a bad way of designing boat, just one that doesn't suit your style.
    http://www.peacefuljourney.ca/
    BEWARE: I am a native french speaker

  45. #45

    Default Re: alternative to epoxy for fairing?

    agreed, does not suit me. for the record, i spent several months researching stitch and glue before i began. including reading sam devlins book twice cover to cover and having it handy as i went. read jim michalak's book ( boatbuilding for beginers), multiple web articles on stitch and glue as well as epoxy, and followed the instructions with my epoxy carefully. used mixing pumps etc. i also studied my plans for 2 weeks before i started (they call for polyester resin, as do the dixie dinghy plans i have) i spent 1 whole weekend reading about scarf joints and how to clamp them, prime them with unthickend epoxy, and mix an epoxy adhesive for the joint. they still failed. the tape was also lifting at the edges, in spite of roughing the surface slightly, applying unthickened epoxy then wetting out and removing excess. whenever i did a new coat on anything i sanded and washed the area, let it dry, still no mixture would bond for fairing (i tried about 20 different blends along the way, thick/ thin, with cabosil/without cabosil. i typically research all my projects relentlessly as i find the research as fun as the project. i have done auto restorations that took 3 years and designed and built 2 homes for myself, i am very patient. i did everything by the book and it just did not work, i wish i knew why. i am not slamming stitch and glue, obviously many folks have made epoxy work, for me it failed in every single application i used it for. i used 1.5 gal up to my stopping point, mostly mixed in 3oz batches, thats 60 batches or so. i tried a few different mixtures, what are the odds i made 60 batches so poorly that they would simply not work at all? my hat is off to sam devlin.

  46. #46
    Join Date
    Apr 2003
    Location
    Dallas and points north
    Posts
    5,862

    Default Re: alternative to epoxy for fairing?

    If all you say is true... and you calibrated your pumps (pumped one squirt from each pump into a measuring cup for exact volume check) and the mixtures were correct (hardener/resin) ... with fresh clean wood joints.... then the epoxy would have to be suspect or contamination somewhere in the process.... or perhaps some of the wrong fiberglass cloth that does not bond to epoxy (Todd Bradshaw can comment on this). The odds are almost 100% that you would not have had failures with one of the major brands... System Three, West, Raka or MAS.... not to mention several other epoxies that are used by forum members. Two clean pieces of wood put together with epoxy and held together for a bit till cure... do not just "fail" ... in my experience (with even a small gap). I can't remember any epoxy failing in any of the work I have done over the past 12 years with System Three General Purpose Resin and hardeners except... when mixed improperly and it just did not get hard at all. My experience with West and MAS are the same... It just doesn't make sense that you have had all these failures... AS you went to the trouble to do the homework... its unlikely you completely F__ked up all those times... so you should have had many examples of epoxy success in joints, etc in this project.

    The amount of failures you report simply imply "somethings rotten in Denmark".... if you know what i mean. Varying thickeners in the epoxy would make no difference... the epoxy system itself would have to be the culprit for all you describe. In defense of epoxy, once you understand its uses and have reliable products, Epoxy allows boat building with fantastic versatility for the reasonably skilled do it yourself-er.

    Take a look at the myriad of tasks performed in the following thread on a most recent build I did for a friend... look at page 1 thru 5... no failures period with System Three.... and I'm confident I would have had the same results with West, Raka, or MAS.... Can you imagine the stress on the scarf joints for the side and bottom panels in the link shown.... the entire success of the craft depends on the epoxy working properly. Thousands of boats have been built with epoxy as a vital bonding adhesive and millions of dollars have been invested.... In your situation, I still say... somethings rotten in Denmark.

    http://forum.woodenboat.com/showthre...ing-and-glueup

    You may end up with a project in the future that requires epoxy... you may consider buying a name brand for a bit more money and develop some piece of mind. I'm curious as to how many positive results you had with the epoxy you used? It should be quite straight forward to glue up a few test materials and even glassed samples... and see how the epoxy performs. You certainly describe plenty of usage... enough to see how consistent the failure is.

    RodB
    Last edited by RodB; 06-12-2011 at 11:35 AM.

  47. #47
    Join Date
    Mar 2008
    Location
    Long Beach, CA
    Posts
    2,457

    Default Re: alternative to epoxy for fairing?

    One problem that seems to have not been addressed (sorry if I missed it) is mix your resin and hardener well BEFORE adding any thickeners!
    Schooner Captains Love to Get Blown Offshore

  48. #48
    Join Date
    Apr 2003
    Location
    Dallas and points north
    Posts
    5,862

    Default Re: alternative to epoxy for fairing?

    Good point... its certainly a possibility...

    R

  49. #49

    Default Re: alternative to epoxy for fairing?

    yes, each batch was mixed 2-3 minutes (as most epoxy manufacturers suggest) before adding thickeners. RodB, this occurred to me yesterday as i cut my boat up. dont know why i did not consider it sooner. i went to great lengths to do the job correctly and in many instances stopped and poured over literature to make sure i performed the next step correctly and still had problems. im a very handy guy, with so many proffessing the ease of use and wonderous properties of epoxy, its hard to believe im incapable of producing "average results". my local marine store has tiny cans of west system, im gonna get some and make some samples with mine and west, ill know by tuesday if somethings "rotten in denmark". honestly i would like to try another stitch and glue design, not because i like it but because i need to know it can be done well. unfortunately i have no faith at this point that they can be made structurally sound, or faired any better than the fire taped sheetrock in my garage. this makes it hard to cut up any of my plywood. i gotta say, you guys on this forum are top notch, i know im tired of listening to me.

  50. #50
    Join Date
    Apr 2003
    Location
    Dallas and points north
    Posts
    5,862

    Default Re: alternative to epoxy for fairing?

    If you test with West or System Three... you will develop some "faith" pdq. Feel free to pm me if you have any questions....

    RodB

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •