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#1
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I am helping a friend who is building a 35' motor trawler. It is planked
with marine ply and epoxy glued and it soon need fairing. Are there any good commercially available epoxy fairing compounds in 5 gallon units? He is debating weather to fair the hull after the glass is laid or more likely fairing before and lightly fairing after the glassing. On the subject of glassing, the designer, Carl Stambaugh, recommended biaxial tape at the corners and has left skin up to the builder and has offered several suggestions. I am thinking that maybe a biaxial covering would be easier for a small crew (2) to handle as compared to woven cloth? The boat has a 2' wide box keel that among other things, will take most of the grounding abuse. He is debating on the glass skin with a Kevlar overlay or just add some roving to the bottom of the box for protection. Any suggestions would be welcome. -- Ron White my boatbuilding web site is: www.concentric.net/~knotreel |
#2
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Depending on the nature of the stitching that holds it together, it can be
harder to get a smoooth surface on biax. System Three has an epoxy fairing compound in bucket quantities. It cures quickly. To me, it looked expensive, but it might save enough labor to be worth it. Ron White wrote: I am helping a friend who is building a 35' motor trawler. It is planked with marine ply and epoxy glued and it soon need fairing. Are there any good commercially available epoxy fairing compounds in 5 gallon units? He is debating weather to fair the hull after the glass is laid or more likely fairing before and lightly fairing after the glassing. On the subject of glassing, the designer, Carl Stambaugh, recommended biaxial tape at the corners and has left skin up to the builder and has offered several suggestions. I am thinking that maybe a biaxial covering would be easier for a small crew (2) to handle as compared to woven cloth? The boat has a 2' wide box keel that among other things, will take most of the grounding abuse. He is debating on the glass skin with a Kevlar overlay or just add some roving to the bottom of the box for protection. Any suggestions would be welcome. -- Ron White my boatbuilding web site is: www.concentric.net/~knotreel |
#3
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Jim,
If these guys are fairing before laying up with epoxy, can't they use poly or vinylester resin with fairing filler or micro balloons? It'd be a lot cheaper. MMC "Jim Conlin" wrote in message ... Depending on the nature of the stitching that holds it together, it can be harder to get a smoooth surface on biax. System Three has an epoxy fairing compound in bucket quantities. It cures quickly. To me, it looked expensive, but it might save enough labor to be worth it. Ron White wrote: I am helping a friend who is building a 35' motor trawler. It is planked with marine ply and epoxy glued and it soon need fairing. Are there any good commercially available epoxy fairing compounds in 5 gallon units? He is debating weather to fair the hull after the glass is laid or more likely fairing before and lightly fairing after the glassing. On the subject of glassing, the designer, Carl Stambaugh, recommended biaxial tape at the corners and has left skin up to the builder and has offered several suggestions. I am thinking that maybe a biaxial covering would be easier for a small crew (2) to handle as compared to woven cloth? The boat has a 2' wide box keel that among other things, will take most of the grounding abuse. He is debating on the glass skin with a Kevlar overlay or just add some roving to the bottom of the box for protection. Any suggestions would be welcome. -- Ron White my boatbuilding web site is: www.concentric.net/~knotreel |
#4
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MMC wrote:
Jim, If these guys are fairing before laying up with epoxy, can't they use poly or vinylester resin with fairing filler or micro balloons? It'd be a lot cheaper. Perhaps they're more interested in doing it right than doing it cheaply. |
#5
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I posted a question on a open "discussion" group, and got a typical wise-ass
response, why am I surprised? The question was based on the adage "epoxy over poly, but never poly over epoxy". I don't know how well polyester or vinylester sticks to plywood, and it was just a question. If guys building boats or refitting old boats can afford not to budget the funds, why bother with building or refitting? Why not just go buy the boat they want? MMC "Brian Nystrom" wrote in message ... MMC wrote: Jim, If these guys are fairing before laying up with epoxy, can't they use poly or vinylester resin with fairing filler or micro balloons? It'd be a lot cheaper. Perhaps they're more interested in doing it right than doing it cheaply. |
#6
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MMC wrote:
I posted a question on a open "discussion" group, and got a typical wise-ass response, why am I surprised? The question was based on the adage "epoxy over poly, but never poly over epoxy". I don't know how well polyester or vinylester sticks to plywood, and it was just a question. Polyester is a poor substitute for epoxy when you're bonding to wood. It doesn't bond nearly as well. If one were to apply epoxy over it, you'd still have a weak bond between the wood and the filler, which would be the weakest link in the chain, so to speak. If guys building boats or refitting old boats can afford not to budget the funds, why bother with building or refitting? Why not just go buy the boat they want? Good question. |
#7
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On Tue, 27 Jul 2004 16:06:02 GMT, "MMC" wrote:
I posted a question on a open "discussion" group, and got a typical wise-ass response, why am I surprised? The question was based on the adage "epoxy over poly, but never poly over epoxy". I don't know how well polyester or vinylester sticks to plywood, and it was just a question. Hi, The problem is that if the wood gets damp the polyester resin will let go, it doesn't have the same adhesive properties of epoxy. For sticking polyester to wood you would need a bonding agent between them. Something like POR 15 or a moisture curing polyurethane pond sealer might do it, a though a trial would definitely be necessary. For small areas or $$$ projects epoxy is the way to go, but if it's a budget project and needs a lot of resin it would be worth checking out the above. cheers, Pete. If guys building boats or refitting old boats can afford not to budget the funds, why bother with building or refitting? Why not just go buy the boat they want? MMC "Brian Nystrom" wrote in message ... MMC wrote: Jim, If these guys are fairing before laying up with epoxy, can't they use poly or vinylester resin with fairing filler or micro balloons? It'd be a lot cheaper. Perhaps they're more interested in doing it right than doing it cheaply. |
#8
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Tape the joints first. Biax tape will be about a 32nd high and is a real
PITA to fair level with the rest of the panel but it is needed for strength so put up with it. Do your rough fairing before laying the glass and then skim coat for final fairing. You can make a very good fairing putty a lot cheaper than the pre-made stuff with equal parts epoxy resin and microballoons and enough cabosil to get the right stiffness. Wet woven cloth is a LOT easier to handle than wet Biax. 45/45 biax is very unstable and will stretch in length and get narrow as you handle it. Dry layup byax is a little more stable but you still have to be careful not to stretch it out of shape. I used the Tom Sawyer approach and got a bunch of volunteers. One person mixing resin, two people wetting out and 3 people laying. We did two layers of DB170 biax and one 6 oz. woven on my 45' hull in 6 hours. After wetting out on a table made from a couple of sheets of melamine we rolled the biax on 2" PVC pipe to carry it to the boat. The only significant increase in cost was a couple of cases of beer when we finished. Ron White wrote: I am helping a friend who is building a 35' motor trawler. It is planked with marine ply and epoxy glued and it soon need fairing. Are there any good commercially available epoxy fairing compounds in 5 gallon units? He is debating weather to fair the hull after the glass is laid or more likely fairing before and lightly fairing after the glassing. On the subject of glassing, the designer, Carl Stambaugh, recommended biaxial tape at the corners and has left skin up to the builder and has offered several suggestions. I am thinking that maybe a biaxial covering would be easier for a small crew (2) to handle as compared to woven cloth? The boat has a 2' wide box keel that among other things, will take most of the grounding abuse. He is debating on the glass skin with a Kevlar overlay or just add some roving to the bottom of the box for protection. Any suggestions would be welcome. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
#9
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![]() "Glenn Ashmore" wrote in message I used the Tom Sawyer approach and got a bunch of volunteers. One person mixing resin, two people wetting out and 3 people laying. We did two layers of DB170 biax and one 6 oz. woven on my 45' hull in 6 hours. After wetting out on a table made from a couple of sheets of melamine we rolled the biax on 2" PVC pipe to carry it to the boat. The only significant increase in cost was a couple of cases of beer when we finished. Glenn, Did you ever get your home made fabric impregnator to work? About how many yards / square meter of fabric did each 6 hour session manage to lay up? And how much experience did your wetting out team have? Thanks -- Evan Gatehouse you'll have to rewrite my email address to get to me ceilydh AT 3web dot net (fools the spammers) |
#10
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I use that same low tech approach since years: wet the fabric on a
large piece of cardboard, roll it and unroll on the hull BUT, some time ago, I saw pictures of a home made impregnator on the web and lost the bookmark. Does anybody know about that? I would like to try. Jacques Mertens http://bateau.com "Evan Gatehouse" wrote in message ... "Glenn Ashmore" wrote in message I used the Tom Sawyer approach and got a bunch of volunteers. One person mixing resin, two people wetting out and 3 people laying. We did two layers of DB170 biax and one 6 oz. woven on my 45' hull in 6 hours. After wetting out on a table made from a couple of sheets of melamine we rolled the biax on 2" PVC pipe to carry it to the boat. The only significant increase in cost was a couple of cases of beer when we finished. Glenn, Did you ever get your home made fabric impregnator to work? About how many yards / square meter of fabric did each 6 hour session manage to lay up? And how much experience did your wetting out team have? Thanks |