Fiberglass repair
- Thread starter Christian Sailing
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as hard as you want it to be, you can use six10 by west systems, or 105/205 with some fillers, to re-build it to the shape you want, just be sure not to make it in a single run, sand it to fair it to it's final shape then add some gelcoat on it.
again, you can do it the easy way or the hard way, just take your time and do it well!!!
FRED
again, you can do it the easy way or the hard way, just take your time and do it well!!!
FRED
Don't plan to gel coat over epoxy- sometimes works, but often not. For that repair I'd use polyester resin and cloth/matt/cloth. The resins are a whole lot cheaper too.
You should use polyester resin and fiberglass mat or tape. Do not use epoxy. It is more expensive and not required for this job and, as mentioned above, often has incompatibility issues with gel coat. You want to sand or grid the busted up part to clean it up and grind back a little so that you remove an inch or two of gelcoat at the perimeter of the damage. Now you can precut pieces of cloth in squares or short rectangular pieces so you have a bunch of them ready to apply after you mix the resin and MEKP, which will "kick off" once combined. Clean the area with acetone. Take a disposable brush and wet out the damaged area and then start building it up with your precut cloth or mat fabric until you have exceeded the shape so that when you carefully grind/sand down the cured repair, you can obtain the desired shape. Clean with Acetone again and then fill with a fiberglass putty (white). Sand smooth and then you are ready to apply the gelcoat. Us a Preval sprayer, which can be found in most automotive shops or better supply stores for marine applications. Mix up the gelcoat and spray it on our repaired area. Let iit cure and then wet sand it to obtain a smooth surface that blends in with the rest of the bow. Use rubbing compound to get the shine back on the new repair spot.
I've used resin with chopped cloth. Where gravity is a problem I have had good success in fashioning a mold with teflon coated aluminum foil and masking tape.
Shape with a disc sander and I sprayed with Krylon paint for pastic. Six years later repair still undetectable. I have also use gel coat on deck surfaces where wear may be an issue.
Shape with a disc sander and I sprayed with Krylon paint for pastic. Six years later repair still undetectable. I have also use gel coat on deck surfaces where wear may be an issue.
Here's a damn good instructional video for the gelcoat repair if youre 'finicky' about cosmetics: "Professional Gelcoat repairs without a MESS" - John Gabriel www.boatrepairvideos.com
Epoxy or Polyester doesnt matter for non structural repairs.
If using epoxy because youre more 'familiar and comfortable' with its usage, be *sure* to thoroughly wash/scrub away all the 'amine blush' with hot soapy water before you do the gelcoat repair. Use a colloidal silica (Cabosil, etc.) 'filler' with either resin system.
Epoxy or Polyester doesnt matter for non structural repairs.
If using epoxy because youre more 'familiar and comfortable' with its usage, be *sure* to thoroughly wash/scrub away all the 'amine blush' with hot soapy water before you do the gelcoat repair. Use a colloidal silica (Cabosil, etc.) 'filler' with either resin system.
Lots of good advice here. Good prep - grinding back to solid material and tapering is important. I would probably fabricate some simple molds or supports for the underside from flexible plastic, then start laying up to make a base to build on, and maybe pre-make a strip of glass cloth to bend around to form the nose... then just fill in with chop, and finish off with a few cloth layers. I might paint instead of gelcoat, depending on what the rest of the deck is like.
I'm too lazy to link to it right now, but the Gougeon Brothers (the West Systems folk) have a paper online that describes the tests they did to assess the relative bond strengths of gelcoat to polyester vs to epoxy, and the conclusiion was that there is no real difference. so there's no downside to using epoxy, other than the higher cost.
Ok I'm less lazy than I thought. The article.
I'm too lazy to link to it right now, but the Gougeon Brothers (the West Systems folk) have a paper online that describes the tests they did to assess the relative bond strengths of gelcoat to polyester vs to epoxy, and the conclusiion was that there is no real difference. so there's no downside to using epoxy, other than the higher cost.
Ok I'm less lazy than I thought. The article.
I use regular white vinegar to remove amine blush from cured epoxy. Works really well.
Amine blush is totally water soluble. The Gougeon's don't even talk about soap anymore, although that can't hurt.
But I have had bad trouble with certain epoxies (SYS 3 in particular) and gelcoat. The gel coat simply refused to cure. I think Sys 3 may be particularly senistive to EXACT ratio mixing.
But I have had bad trouble with certain epoxies (SYS 3 in particular) and gelcoat. The gel coat simply refused to cure. I think Sys 3 may be particularly senistive to EXACT ratio mixing.
"Normal" gelcoat (used in the factory) only cures if it's in a mold or there's film over it; it will not cure properly otherwise. "topcoat" (the gelcoat most often sold for repairs) has a wax that migrates to the surface to permit curing in "air". Are you sure this wasn't the gelcoat problem?
If you apply a parting fluid (aka - mold release agent) such as polyvinyl alcohol you not have a problem with the 'curing' of most gelcoats. Spray or brush on.
http://www.evercoat.com/productDetail.aspx?pID=162
Good News and Bad News
The good news is:
This is a great project to learn how to work with fiberglass. Aside from pride in workmanship esthetics are not important on this job and it will sail the same no matter how butchered or how perfect the job is. Other than sealing the deck and the hull so that it does not leak all the rest is cosmetic.
Do not worry about gelcoat a can of Krylon makes an acceptable finish
Undoubtedly if the boat is used much after the repair you will have another opportunity to repeat the job and perfect your Sunfish nose repair skills.
When you do perfect your skills there will be many others coming to you for your skill.
The Bad News is
It is a tough are to get a good bond between the old and new fiberglass as you need to cut back a bevel of at least six to one and the hull is just not that thick other than the deck.
Undoubtedly if the boat is used much after the repair you will have another opportunity to repeat the job and perfect your Sunfish nose repair skills.
When you do perfect your skills there will be many others coming to you for your skill.
Suggestions:
Check with the folks who manage the youth sailing programs at your club or in your area. You could probably work out a deal with them to have someone fix it. You could also offer to help with the repairs on the programs boats and have their guys teach you the tricks and apply them to your boat. A word of caution however I did exactly that and the Sunfish I was hoping to repair has not been touched since. I get real busy with our programs four coach boat and forty something Optis, Sunfish, and 420s to the point that now my boats go neglected and almost unused. It is a $600 hull don’t make a bigger job of it than it is worth.
The good news is:
This is a great project to learn how to work with fiberglass. Aside from pride in workmanship esthetics are not important on this job and it will sail the same no matter how butchered or how perfect the job is. Other than sealing the deck and the hull so that it does not leak all the rest is cosmetic.
Do not worry about gelcoat a can of Krylon makes an acceptable finish
Undoubtedly if the boat is used much after the repair you will have another opportunity to repeat the job and perfect your Sunfish nose repair skills.
When you do perfect your skills there will be many others coming to you for your skill.
The Bad News is
It is a tough are to get a good bond between the old and new fiberglass as you need to cut back a bevel of at least six to one and the hull is just not that thick other than the deck.
Undoubtedly if the boat is used much after the repair you will have another opportunity to repeat the job and perfect your Sunfish nose repair skills.
When you do perfect your skills there will be many others coming to you for your skill.
Suggestions:
Check with the folks who manage the youth sailing programs at your club or in your area. You could probably work out a deal with them to have someone fix it. You could also offer to help with the repairs on the programs boats and have their guys teach you the tricks and apply them to your boat. A word of caution however I did exactly that and the Sunfish I was hoping to repair has not been touched since. I get real busy with our programs four coach boat and forty something Optis, Sunfish, and 420s to the point that now my boats go neglected and almost unused. It is a $600 hull don’t make a bigger job of it than it is worth.
Home Depot carries them too, about $6 for the whole kit, $5 for just the powerhead. I just gel coated my transom and the Preval sprayer worked great. Thin with Styrene, I got mine from West Marine. Was special order but hand delivered to the store in 3 days.
That is a very good point, and a decent question, but yes, I'm sure.
Been messing with repairing boats since about 1968. Started using epoxy in 1976. I know the difference between lay up resin and finishing resin.
all good advise here.
That nose will get broken again, so polyester resin is the way to go.
epoxy doesn't like to stick to epoxy, so 2nd time will be a worse looking repair.
barnacle bill nailed it. or go with the statue!
That nose will get broken again, so polyester resin is the way to go.
epoxy doesn't like to stick to epoxy, so 2nd time will be a worse looking repair.
barnacle bill nailed it. or go with the statue!
To enlarge on something-
Epoxy will stick extremely well to epoxy. Many many epoxy /glass boats testify to that
Epoxy will stick extremely well to polyester resin. Many many repairs done with epoxy on polyester glass boats attest to that.
Polyester resin sometimes has a difficult time sticking to epoxy. But then polyester resin is really not an adhesive, as epoxy is. Works very well in a matrix with fiberglass (mat or cloth). Most of us sail boats built that way, but doesn't really adhere to even bare wood all that well.
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