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Ljaybo41
06-24-2018, 01:31 PM
I'm building a 13 ft catboat designed by Paul Fisher, the Petrel 13. All the seams and frames are filleted with system 3 easy fillet and sanded ready for taping.

Since I'm a novice, I started at the stern in an area that will be covered over by a bench and not seen. I used three inch 8 oz tape and it leaves a significant ridge along the edge. I'll sand that down but I'm concerned about how to remove the blush from the weave before I use a fairing compound to fill it in. Will a scotch rite pad be able to get in to all the ridges? Using west epoxy so blush is a issue.

For the more visible seams, If I switch to cutting my own tape from cloth to eliminate the ridge, can I wet on wet with fairing compound after laying the tape to fill in the weave?

Thanks everyone, building my first has given me a true appreciation for the craftsmanship I've seen on this forum.

Gib Etheridge
06-24-2018, 01:43 PM
One approach would be to use a razor knife to remove the selvedged edges as soon as the epoxy reaches the tacky state then apply the wet on wet. It's less work and done sooner that way. Just make sure you cut all the way thru so you don't peel the entire strip up when you peel off the partially cured resin/glass selvedged edge.

DeniseO30
06-24-2018, 01:53 PM
does it really matter on the inside? Gib's way works well. Dunno why you be getting blush with West. It washes off
If you want to sand the edge of the tape after it's cured hard that works, use a narrow block of wood instead of wide. only sand the tape edge.

tink
06-24-2018, 02:14 PM
I use peel ply, it goes over the tape after you have laminated it but still wet. The peel ply is them placed over the wet tape an rollered or brushed to flatten it and completely cover the tape absorbing some of the resin. When the resin has cured you pull off the peel ply. Much better finish, reduced sanding and no blush. Peel ply is available as a thin rolls, 3 inches etc.

See, explains it better than I have https://compositeenvisions.com/documents/amine-blush.pdf

amish rob
06-24-2018, 02:29 PM
Cut strips of plastic film a bit wider than the tape.

Lay out the tape, and saturate with epoxy right on the plastic.

Lay tape and plastic down on the seam, with the plastic out. That’s obvious, right? :)

Squeegee over the plastic to firmly press plastic and tape down into place. The plastic won’t absorb epoxy, so whatever little excess there is is forced to form little “ramps” which fair out those little ridges.

It works.

Peace,
Robert

P.S. You can also use a plane set fine to trim off the ridges on firm but not fully cured epoxy. It takes a while to cure, incidentally, so protect yourself from green epoxy, especially the dust.

Breakaway
06-24-2018, 03:02 PM
I second Rob's method.

Also, i prefer to fill the weave with hot coats( before full cure). This way blush is no issue and i can tool the squeeze out with a plastic spreader to fair in the edge.

Finally, next time consider making your own tape from cloth strips cut on a bias. No selvedge edge , conforms to shape better and cheaper too.


Kevin


Sent from my iPhone using Tapatalk Pro

JimD
06-24-2018, 03:05 PM
As well as a razor knife you can use a sharp wood chisel or other wood carving tool such as these, which I have used with much success

https://secure.img1-ag.wfcdn.com/im/43129495/resize-h400-w400%5Ecompr-r85/4392/43925797/Carving+Tool.jpg

. The scotchbrite pad should work. Make sure you are thorough and rinse well. For the future, consider applying the filler/fairing mix before the epoxy on the cloth is fully cured. Then you won't have to worry about blush interfering with the bond.

NOTE: making your own tape with strips of cloth is likely to end up with a big unravelly mess. Much easier in the long run to use proper tape and trim the seam ridge after. I speak from personal experience.

amish rob
06-24-2018, 03:49 PM
As well as a razor knife you can use a sharp wood chisel or other wood carving tool such as these, which I have used with much success

https://secure.img1-ag.wfcdn.com/im/43129495/resize-h400-w400%5Ecompr-r85/4392/43925797/Carving+Tool.jpg

. The scotchbrite pad should work. Make sure you are thorough and rinse well. For the future, consider applying the filler/fairing mix before the epoxy on the cloth is fully cured. Then you won't have to worry about blush interfering with the bond.

NOTE: making your own tape with strips of cloth is likely to end up with a big unravelly mess. Much easier in the long run to use proper tape and trim the seam ridge after. I speak from personal experience.

Agreed. A 1” chisel rocks, if you use a deft touch. The plane helps keep from digging in. I have this little trimming plane that works wonders for peeling off the little ridge from tapes.

Peace,
Robert

P.S. If it’s to be painted, I also add filler to my fill coats. A ketchup type consistency is nice for just filling the weave and not leaving too much extra.

Ljaybo41
06-24-2018, 03:58 PM
Ok, I see that trimming the ridge is much easier than sanding. In order to do hot coats to fill the weave, do I use epoxy, easy fillet or filling / fairing compounds? Is the fairing compound easier to sand then easy fillet? No fairing compound on hand but I do have a large tub of easy fillet. Thanks for all the help. I'll post some pics once I'm ready to flip the hull.

Ljaybo41
06-24-2018, 04:00 PM
Ok, just read that all again. Understood to use filler fairing for hot coats. Thanks again everyone!

Oldad
06-24-2018, 04:00 PM
I use a well sharpened scraper to remove the "ridge" the next day. A paint scraper will work but if you check Jamestown or other suppliers you will find very nice scrapers with various contours for cleaning up epoxy work. Works great on drips, runs, fillets, etc. BTW, I always use slow hardener (it cures to the touch overnight so there is no blush)

Todd Bradshaw
06-24-2018, 06:00 PM
A medium soft scrub brush (like a dishwashing brush) and water will scrub blush out of the weave if it is too late to hot coat it. No big deal.

Mo 'Poxy
06-24-2018, 09:36 PM
System 3 sells non-blushing poxy.

Dusty Yevsky
06-25-2018, 12:44 AM
A flush plane makes very quick work of a selvedge, even one that's fully cured. Unlike a chisel the bevel configuration of these allows the blade to lie flat against the work piece and easily trims the protrusion. Lee Valley makes one for a reasonable price. It's an indispensable tool in my workshop. A little sanding to feather the edge and Bob's yer uncle.

http://www.leevalley.com/en/wood/page.aspx?p=32664&cat=1,230,41182

tink
06-25-2018, 01:49 AM
I like Bobs method I will give that ago.
I am very unsure about second coats and filling the weave sounds like extra effort, weight and expense. On internal joints I only have the paint after removing the peel ply.

On external chines I don’t tape, other than the keel. For the external ones after I put the peel ply on a tightly pull on normal to the direction of the joint tight parcel tape useing a tape gun. The tape runs about six inches each side of the chine and lots os strips covering all of the peel ply. This acts like vacuum baging the joint and packs everything down nicely and eliminates filling unless something goes a bit wrong - usually at the corner of the stem.

Once the cloth is wetted out any additional resin is a complete waste. I have never had a joint fail.

swoody126
06-25-2018, 07:24 AM
i have had good results using the blade from a CABBAGE FILE(SureForm) that has been removed from the holder

usedtowaz they made a short one on a handle that had a fair amount of rocker in the blade and it worked really well at removing the edge ridge

now i simply hold a blade in my hand pressing the cutting teeth against the ridge w/ my fore finger as i drag it

as for removing drips n drools i've found a heat gun will soften them so they can be scraped off/smooth easily

sw

John Meachen
06-26-2018, 04:29 PM
For the umpteenth time I will reiterate the technique developed by Peter Conway in the 1970's for taping chines.The inside isn't too important for cosmetics,but the outside is made much easier if you bevel the edge of the panel.Remove one ply veneer thickness at the edge and taper it back to nothing about three quarters of an inch beyond the edge of the tape.When bonded it then becomes much easier to add a tiny skim of filler to fair the hull.

tink
06-27-2018, 12:25 AM
For the umpteenth time I will reiterate the technique developed by Peter Conway in the 1970's for taping chines.The inside isn't too important for cosmetics,but the outside is made much easier if you bevel the edge of the panel.Remove one ply veneer thickness at the edge and taper it back to nothing about three quarters of an inch beyond the edge of the tape.When bonded it then becomes much easier to add a tiny skim of filler to fair the hull.
It it might be the umpteenth time you have posted and I do have a dull recollection of hearing it before but it is well worth pointing it out again. Thanks for posting