A piece of bad advice on the WBF

[L.W. Baxter]

I don't want to drag anyone out in the street for a public flogging, but I do want to make sure nobody else tries this:


apply epoxy to the fiberglass cloth - cover the wet epoxy with wax paper or poly plastic. Let the epoxy get hard - peel away the plastic or wax paper. Surface tension will keep the epoxy from draining out of the weave - result - less epoxy, less weight, smooth surfaces
I just glassed one side of my 26' Bartender today, and thought I would try this trick using wax paper.

First, it doesn't really work. The paper does flatten off the surface, but you end up with lots of pinholes, if not pock marks and craters, because the "surface tension" previously mentioned starves parts of the weave in order to create a raised, flat surface.

Second, particularly important on vertical surfaces, the paper covers up your work so that you can't go back and remove excess epoxy if it starts to sag. I ended up with alot of wrinkles that I would have easily squeegeed off under normal circumstances. Maybe if I were more expert, I would not have left any excess resin anywhere, but I'm not, so I did. Now I get to scrape, sand and fair my way back to a smooth surface like the one I started with.

And third, and most importantly, if you use wax paper, when you pull off the paper, a significant trace of wax residue is left on the epoxy! I know because I can scrape it off with my fingernail.

I'm going to try to fix this tomorrow. I'll check in the morning, maybe somebody has a suggestion for removing the wax? I'm hoping it will sand off easily, as I won't be able to go at it very hard without cutting into the glass.

--Lee

[ 03-05-2005, 03:58 PM: Message edited by: L.W. Baxter ]

[sawcutmill]

Fiberglassing is not easy, and that is why it costs so much to have professionals do it,it is Not rocket science, but then again it is Chemistry. Practice makes perfect.One needs to be careful when reading other posts about certain subjects, do your due diligence.Use the forum search for more answers to any particular question. good luck.
Have Mill Will Travel...

[BillyBudd]

Lee, wax and epoxy don't mix so get that stuff off of the epoxy before proceeding. Scrape, whatever. On advice and acceptance thereof, several thoughts leap to the keyboard. Try a small sample first--this goes for just about everything, you know, from marriage to eating oatmeal. Epoxy mfrs. are creating different viscosity liquids so one guy's advice won't work for the next guy's juice. Lastly, fine surfaces for me are not easily had...or else I'd have lots of them instead of just a few. If there were true blue shortcuts to this rich man's necessity, poor man's folly or dream or whatever, I'd guess the shortcut would be a clogged highway.

[Ian McColgin]

Ahoy Lee.

Like Mlke I feel your pain. Like Mlke I also suspect that you should peel that layer off if you can't trust your ability to get ALL the voids out.

My experience is confined to applying various glass cloths over wood or other glass. I've never used mat or unidirectional.

My own preferred method is to put a thin layer of epoxy on the surface to the covered and get the glass laid on that. I use hard rollers and gloved hands to get the glass down and void free but I do not attempt to fill the weave at this point. Lots of white. Because glass cloth floats in epoxy on horizontal surfaces and sags off on anything else, I let that cure to moderate tack and do any trimming before I go for a soaker coat.

The goal here is to put the second layer of epoxy on before the first amine blush starts, so it'll bond well, but after the bonding layer has a chance to set up enough that the cloth won't sag away from the surface. If I can't get it soon enough I let the bonding layer cure completely and give the job an acetone rubdown, which seems to be enough to get everything to cure well bonded.

Anyway, I really roll hard and smush that soaker layer in with rollers and plastic spatulae. I like to get the glass all transparent but the epoxy pushed so hard that there's a trace of the weave rippling the surface. To that I add just a bit more epoxy smoothing it carefully with flat spatulae as i go along. A good motion can move the puddle of epoxy along leaving near perfection in its wake.

It's incredibly tedious but far easier than huge grinding later.

Edited to add: Had I seen the post that led you astray, I might have questioned it. I can't figure out how this bright idea was meant to work from the quote you give but sometimes a few questions either reveal the flaws in a bright idea or cause the original poster to give enough additional information that the complete process is revealed in all its glory. The method does not sound very promicing to me but perhaps there is more info that would make it ok for some limited applications. But I doubt it as the method really does depend upon starving the subsurface. You want light, just use lighter cloth and never make big puddles. Ah well.

G'luck

[ 03-04-2005, 08:30 AM: Message edited by: Ian McColgin ]

[Paul Maselli]

A good glass job is all in the preperation first, execution second. By this I mean that every single glass panel should be precut and laid out for fast and easy access when you have your resin mixed.

Wax paper or Poly film should never come into the equation. These will most certainly give you the results you have obtained. Ian is on the right track for getting the cloth down smooth and tight in a wetted surface. Then go back and apply the resin to saturate the fibers. This applies to glass, e glass, or matte fibers as well, the only problem is when using matte too much smoothing will fuzz up the surface fibers, keep this to a minimim, use a stippling action with your brushes to push resin into the matte.

The only application for using wax is in the application of a polyester based (ughhh) gelcoat repair that is cured open to the air. Gelcoat and all polyester resins are anerobic cures, hence they require the absence of atmospheric oxygen to fully cure. When gel coat is sprayed into a mold and a glass schedule is layed up it naturally cures in an anerobic state.

If you need to do a localized repair to a gelcoat surface (not really applicable to the WBF) Wax suspended in styrene is used, it is added to your gelcoat and the suspended waxes float to the surface to create the anerobic cure. Finishing resins have wax added and laminating resins do not so the surface remains tacky for the next course of the layup.

Fiberglassing is not hard, it does take preparation and a fastidious work habit. Anyone can do a lousy job, get all your ducks in a row before you start and you'll see better results.

Peel off the bad layup and re-do the panel. You'll be much happier with the reuslts obtained without a film barrier on the surface.

Good Luck.

[Brian Palmer]

This technique does work for SMALL repairs to a fiberglass part. We did this when repairing fiberglass whitewater canoes and kayaks. Sort of a "poor man's vacuum bagging." It increases the glass-resin ratio for a stronger repair. But, in this case we were not intending to cover with additional layers of cloth or paint.

I would not use it to create a smooth surface on a wood surface that you are encapsulating with glass and resin for the reasons identified.

-- Brian

[JimConlin]

If your wrinkles are just extra dribbles of epoxy on top of the cloth, getting the surface fair will require sanding or scraping them off. If scraping, it's easier when the epoxy is newer. If, OTOH, there are wrinkles in the cloth, getting he surface fair will require sanding down through the glass. Not good but not fatal. If you still can peel the glass, i'd consider it.

Removing the wax residue is no big thing. Use TSP in hot water and a Scotchbrite pad. Rinse and dry thoroughly.

Next time, i suggest that you use peel-ply. Peel-ply is a light nylon or dacron taffeta fabric. It's inexpensive (about $2/yd. in 60" width). Lay it over the saturated glass and squeegee vigorously from the center to the edges, expelling excess epoxy and bubbles. Some bubbles and excess googe exude through the fabric. I use plastic auto body filler spreaders, available from the fiberglass suppliers and from body shop supply joints. The peelply is peeled off after the epoxy has cured and leaves a flat slightly textured surface with few bubbles or wobbles. If you get it right, little sanding or fairing is needed. Experiment first on a smaller part.

One source of bubbles when glassing (or varnishing) un-sealed wood is gas expanding from the pores of the wood. This out-gassing happens when the temperature is rising. If you have a heat issue in your shop, get the patient as warm as you can before glassing it and let the temperature decline a bit thereafter.

Good luck,
Jim

[Tom Lathrop]

In relation to Baxter's original post, many have been using plastic film to smooth out small repairs jobs on FG boats for a long time. In a small area, it's not too hard to push the bubbles out to one side and teh resulting repair surface needs very litle fairing to finish it.

On a large area, it seems impossible to get the bubbles out and it's nearly impossible to fill the holes later. From a distance, it looks great but, up close it's like Swiss cheese.

Many advise wax paper over epoxy as a separator but I find that it sticks and, like others say, it leaves a wax coating. Plastic film is cheap and far better.

Good judgement comes from experience. Experience comes from bad judgement.

[ 03-04-2005, 09:11 AM: Message edited by: Tom Lathrop ]

[StevenBauer]

Lee, search back for John Blazy's plastic film techniques. Barrett in Wash. had some success with his methods, too. He doesn't use wax paper (shudder) or regular poly, he gets some sort of stiffer more ridgid plastic. I'll look tonight, no time now.

Steven

[Jon Curtis]

I've had good results wetting out the cloth on a table over poly sheeting and then lifting it off & placing the wet cloth on the vertical surface. This was on a "BIG" job with 12 oz biaxial cloth with 3/4 oz matte stiched to the back. I also used MAS slow resin & hardener in hot virginia weather. The biggest problem I had was keeping the epoxy from wicking out of the upper most verticle edge. This method is good for large areas and heavy cloth with two people. One person using this method will usually wrap himself rather than the boat. smile.gif

[George Roberts]

L.W. Baxter ---

A lot of bad ideas are spread by posts, here and elsewhere.

Those who fight the bad ideas get tired after a while and stop fighting.

[Ian McColgin]

And, as we've see above, a lot of good ideas can go bad in the wrong context. This happens a lot in quick posts where commentators can't see the whole job and questioners might or might not have given enough information. Signals cross. It's worth the thorough airing. I might have learned a couple of tricks in this very thread and am thankful that the occasion arose. When I go to try something out, maybe I'll remember enough to get it right or maybe it'll be one of those "Oh-Oh" moments.

[John of Phoenix]

On the wax, it’s like amine blush, sanding will only rub it in, spread it around and cause adhesion problems with the next coat of epoxy. Mineral spirits or similar will remove it, then wash thoroughly with soap and water and finish with a clean rinse. A pain yes, but wax/blush will really give you problems if it’s not cleaned up.

Instead of wax paper, rubber mats, poly whatever, why not use what was invented for this purpose, PEEL PLY. Guys who make airplanes for a hobby wouldn’t think of NOT using this stuff, but they do a lot of glassing using vacuum bagging on polyfoam airfoils where you have to have a release fabric. Also, they can’t afford the extra weight of three or four coats of epoxy or to sand too deeply into the glass.

Peel ply is a godsend and if you haven’t tried it you’re really missing out on a great tool that will greatly simplify your fiberglassing. You’ll not only save epoxy, you’ll save an amazing amount of time. The typical glassing job requires putting down the fabric and a coat of epoxy. When that’s cured it’s followed by two, three or more coats of epoxy, with or without fillers, to fill the weave of the glass. Each coat has to be prepped and if you’ve done it you know what a chore it is and all the things that can go wrong not to mention all the sanding. Damn all that sanding. It’s days of work.

There’s been a couple of threads on peel ply in the past but, for some reason, it’s still not widely used. Basically, peel ply is a light weight Dacron or Nylon fabric that is laid over the wetted out fiberglass on the first coat of epoxy. The resin is then squeegeed a second time to wet out the peel ply. You may need to add a little more resin here and there, but mostly you’re just redoing the resin that’s already there. When the epoxy cures, the peel ply is removed and you're left with a smooth, blush free, surface that’s practically ready to paint. There is a very slight texture from the pattern on the peel ply, but it is VERY slight and easily sanded.

I think it was Tom Lathrop who said he got a similar fabric from a fabric store so I tried a test batch from a local shop. The results were so-so at best, and the cost was prohibitive. About $6 a running yard for some Dacron and it was really tough to get back off. I shopped the net and found various products from $7.75 to $2.57. The good news is that the real stuff, authentic peel ply, called "Econo Ply J", in a 60" width by 25 yard roll, is available from the manufacturer for $47.25 + a few more for shipping. (Probably spend that much on sandpaper anyway.) Works out to about $2 a running yard.

And this stuff really works. I did the hull of my Weekender in one weekend. (Very punny.) The glass and peel ply were applied on Saturday morning and afternoon, the peel ply was pulled off Sunday morning and the sanding (used 6 discs of 80 grit with a 6” Porter Cable random orbital sander in six hours) was completed in time for an early supper. One coat and done!! DONE! Baby’s bottom smooth and ready to paint (after a week or so to cure) in less than 36 hours.

It’s also great when making fillets. Just lay the epoxy goop fillet, add glass tape if it's a structural joint, apply the peel ply, wet it out and smooth the joint with a squeege. Let the resin cure, pull the peel ply off and you’ve got as smooth a joint as you could ever ask for without ANY sanding, all in one step.

Check it out at Airtech Online. Econo Ply J is what I use.

https://www.airtechonline.com/Airtechstore/dept.asp?Dept_ID=5

[Elco's]

Its amazing how often I've read advice on here that was repeated from a book (or previous forum posts) and not from experience.

buyer beware

[JimConlin]

There's an echo in here.
That's the stuff.

[L.W. Baxter]

Thanks for the help, folks.

I think I wasn't clear about the pock marks. I didn't really mean to say that the cloth had been "starved" to the point of not having resin in it, just that there was not enough resin in the cloth to create a flat, lifted surface. I don't have many air bubbles or voids. I'm confident that I got good adhesion, so in this case, peeling off and starting over doesn't seem neccessary.

And the wrinkling I referenced appears to be in the resin only, not the cloth. I'll get it smoothed back down, eventually.

I do have to make like Ralph Macchio and get the "wax off", however. I might take a stab at the mineral spirits. I don't suppose acetone would be a good choice here?

Maybe we could call this particular method of glassing the "lost wax process."

As you can see, I've gone from depressed to morbidly resigned.

I also got a batch of hardner that turned part of my hull purple, which is not a structural problem, but it makes me kinda sick to look at it. I'm going to cover with some white pigment in my top coat.

Ah well, nothing that a bunch of wasted time in the shop can't cure.

--Lee

P.S., thanks for the sympathy people, I feel a little better.

[ 03-04-2005, 01:09 PM: Message edited by: L.W. Baxter ]

[Elco's]

moisture in the hardener will tint the epoxy purple-brownish ect. The purple can also be from moisture in the substrate reacting with the hardener in the mixed epoxy. Although, that is generally a whitishness.

[Mike Vogdes]

WEST hardner will turn purple when it gets a little age to it, I don't believe it affects its performance.

[George Roberts]

Mike ---

I was apologizing for my not correcting that bad idea and applauding his attempt:

"but I do want to make sure nobody else tries this"

to do so and to accept that he will one day give up on trying.

[John of Phoenix]

I might take a stab at the mineral spirits. I don't suppose acetone would be a good choice here?
Acetone will work if it dissolves the wax, which it should. Basically you want anything that will 1-disolve the wax(easy) 2-clean up with soap and water(easy) 3-(IMPORTANT)be easy to detect if it didn't clean up properly(not so easy). Try a small section with acetone and another with mineral spirits and see how each works. As an experiment, do a “not so good job” on part of it to see if you can detect any residue that doesn’t wash off. That’s the tricky part, residue.

I've used acetone, ammonia, alcohol and mineral spirits on blush. I prefer the mineral spirits because it leaves a film. Yea, that sounds odd but it’s easy to clean with a 3M scrub pad and soap and water and it’s easy to see what you miss. Not "if" you miss, "what" you miss because you will miss a lot. When that film is gone, i.e. no water beads, everything’s clean. With the others, you’re never sure if there’s some residue left because they all evaporate and the water doesn’t bead up. Another advantage of mineral spirits is that it’s not as hard on a person’s body as some of the others. MEK, whew!!

But honestly, just TRY the peel ply. You won’t be sorry, especially on a 26’ hull. You’ll save a TON of work. No blush, no washing, no runs/bugs/dings in the goop, one coat coverage, a FRACTION of the sanding, etc.

[bainbridgeisland]

Been using nylon vacuum bagging film to create very high-end fiberglass parts for years. One-way that works is similar to the method you tried but with some important variations. Go ahead and wet out the fiberglass as you normally would. Next, cover the area with nylon vacuum bagging film. Dribble some olive oil on the outside of the film for lubrication and then use a rubber squeegee to re-distribute the resin under the film as needed. Don't press too hard. You will find this produces a very smooth finish assuming you have enough skill with the squeegee.

This method is related to a little known production method sometimes known as "edge bled vacuum bagging". It produces parts near the quality of autoclave processing but is far less expensive. Once you become proficient with the method, it always works, even on new parts (unlike infusion processing). However, it does take a skilled shipwright/laminator to be fully successful.

[Bayboat]

What tales of woe. This thread is ample testimony for a recommendation that we all get out our pitchforks and scythes and go after whoever promotes sheathing with fiberglass. It obviously takes more fussing than it's worth. (Remember when the cat got stuck in it and wasn't discovered until several hours later...?) If it must be, how about a new forum for wood/fiberglass boatbuilding? Then the rest of us can continue talking about and building boats that don't need sheathing to keep the water out. Harrumpfh! from a licensed curmudgeon. Oops...incoming...

[Gary E]

And you guys are building WOODEN BOATS ??

ok, admit it, your building FIBERGLASS boats but dont want to make a mold so you put the glass on whut ya think is a wood boat.

[JimJ]

And you guys are building WOODEN BOATS ??

ok, admit it, your building FIBERGLASS boats but dont want to make a mold so you put the glass on whut ya think is a wood boat. Nah. It is just extra strong paint :D

[bainbridgeisland]

Originally posted by Gary E:
And you guys are building WOODEN BOATS ??Treating this as a serious question- I think boats are wood if primary structural strength is wood. If you are adverse to abrasion protection or properly applied coatings, sometimes including fiberglass, you had better stop using stainless steel, modern glues, modern paint, sails, wire rope, blocks, engines and so forth.

Fact is; use the materials that make sense for the job. (Wood often makes sense.) You can argue about what makes sense for a particular job but will find professional shipwrights trained 50-years ago, and before, generally subscribe to this principle.

Also remember, those of us enjoying extra-curricular boat building should enjoy the project. If fiberglass keeps you from enjoying the project, use alternatives.

[Paul Pless]

LW Baxter,

regarding the cleaning of the wax off with acetone,

I recently had a multicoat epoxy floor system installed in my laboratory, soon afterwards a roofer tracked asphalt tar all over it, the epoxy manufacturer (Shell) recommended that I use xylene to clean the floor up with as it is the main component in the hardener of the epoxy, it would do nothing to weaken the set, bond and/or surface of already cured epoxy.

Paul

[L.W. Baxter]

Well, I scraped and sanded and washed and filled and squeegeed, and it felt so good I went ahead and glassed the other side of the boat! Waiting now to do some topcoating...

Just as a point of fact, the Bartender doesn't rely on glass to make it float. Glassing the hull is optional, and I chose to do it. I can't recall exactly why at the moment, but I'm sure it will come to me eventually.

As far as the great fiberglass/wood debate goes, I'll just say... You do what you gotta do to build the boat you wanna have.

Also, I will point out I've gotten lots of excellent advice on this forum. And I don't blame anybody for my impetuous decision to try an uncommon and untested method.

Sayyy, that peel ply sounds promising! ;) :D

--Lee

[ssor]

lay up csm and cloth and no matter how hard you try to get full compaction, laying peelply over it and rolling that will improve the work.

[Peter Malcolm Jardine]

Bad advice on the WBF Nonsense. Free advice is worth every cent you pay for it. ;)

Sounds like everything worked out L.W. I personally liked John Blazy's method on his boat, and he had pictures to prove it. ;)

[BHM]

Lee

When building the "ICON" , I found a very effective method of applying the epoxy. I know the feeling and apprehension of the task , as mine was 4' longer than your project. First, I measured my resin and hardner in large paper cup batches. I had several ready to go on hand and then just did the actual mixing as I needed. I always could keep a wet edge.... BUT HERE IS THE TRICK.. I would pour a puddle of epoxy along the top of the side and using a LARGE drywall spatula/knife (mine is 14") work the puddle, like a "plasterer" does a house. You will have full control, of the product.... forget the roller. I used it only for very small spots, less than 5% of the job. Important note here.... Apply the cloth dry first, work out all the wrinkles, get it right before going any further. You'll find you will have not wasted your product, and it will "wet" through nicely.

Brent http://www.imagestation.com/picture/sraid160/p6c88d59567a998ec8fd545001c69189e/f4eefe50.jpg

[L.W. Baxter]

Sounds like everything worked out Yes it did.

I've got both sides of my boat glassed now. Funny thing, the use of the wax paper on one side of the hull, though the wrong material for the job (and causing a few hours extra work to remove the wax), ended up creating a smoother surface, and using less epoxy to fill than the side I did conventionally. I think when I go to sheath the bottom, I may very well try the peel ply method described here by several members.

And I just modified the title of this thread, as I felt the original unintentionally slandered the WBF. Just look at all the helpful advice, sharing of tecniques, and general sociability on, ironically enough, this very thread!

I hope that the fellow who posted the wax paper idea won't hesitate to share his views with me in the future. I should have followed up his tip with a little more research and questions, in the process arriving at the right material for the job. No hard feelings from my end.

The only people who never make a mistake are those who won't risk the exposure. Man, I leave my ass hanging out all the time, and I get the occasional spanking...but I hear that it builds character.

--Lee

[paul oman]

Lee -

I'm the guy who posted the initial suggestion. Glad you figured it out. I should have suggested there is a learning curve like all things in boat building. Also, I've mostly used it to fill the weave AFTER the initial epoxy / cloth work. It can get old trying to fill the weave and seeing it return even after several coats of epoxy. Here covering with the plastic (or wax paper in a pinch) seems to get the weave filled in within a single topcoat of epoxy.

What's nice is that I too learned a lot from this post. Especially the actual products (much better than plastic bag material or wax paper) that are actually sold for this method and that a few serous epoxy guys use this method, perhaps more than most of us are aware of.

The really best use of this method is when working with thickened epoxy or epoxy putties. they tend stick to you putty knife etc. as that folks like me end up using a lot our epoxy putty around a 'hole' and the never getting it sanded flush. Put the paper over the epoxy putty and you can smooth it out etc. easily and neatly thru the pastic film. Extra nice when the thickened epoxy has some unwanted texture to it. Use of the film/paper blots out the surface texture and leaves a smooth finish (as smooth as the plastic film) which, in my cases, is smoother usually smoother than the surrounding areas.

Paul Oman
progressive epoxy polymers
(company name provided in the spirit of FULL DISCLOSURE) I seem to get in trouble when I include my professional bias, but feel if I don't disclose it I'm somehow hiding my bias from all of you. It is not for self promotion as some have suggested. I spent years as a high tech corporate marketing consultant in Houston. For self promotion I would log in as a some other person and pretending to be an unattached third party, give glowing reports of products and prices, etc. (and such '3rd party' recommendations are common on this forum). I won't do that. I'm just a boat nut like the rest of you. I own 19 boats (all under 16 ft) all in my backyard - plus a 3 ft radio controlled sailboat raising the count to 20! - just had to get this off my chest. - paul

[L.W. Baxter]

Ahh so!

Applying the paper or plastic on the fill coat is quite a different thing. A few extra words of explanation would have been useful, eh? Though I still think I would avoid promoting wax paper for the purpose. I'll go back to wrapping fish with it, myself.

--Lee

[John of Phoenix]

Wrapping fish, good one. :D :D