I have a few small areas of peeling gel coat that I need to repair. The fiberglass underneath is solid. I am thinking of just sanding off the loose stuff, putting a thin layer of epoxy over the area, sanding smooth and painting. I’ve heard that Krylon Fusion spray paint for plastic works reasonably well for painting epoxy. Any thoughts on this? Obviously not the best repair but it is an old canoe and I don’t want to spend much on it. I also don’t care if it looks perfect as long as it is smooth and strong.
I wouldn’t complicate things.
You say the glass is solid with a few spots of peeling gelcoat? Clean up the spots and apply a new coat of gelcoat to them. Done. Simple.
good stuff …
.... use this for the fill and fairing , put whatever you want over it ... gelcoat , paint , nothing , etc. .
Sand to the cloth , sterilize (acetone) , fill once or more times (build up as req.) , sand to fair , finish coat opt. .
I think what you have going on is blistering , don't be afraid to get aggressive with your prep work (remove what don't look good and sound) , and then fill it back up ... my advice , nix the epoxy idea .
ps., ... don't have to purchase at the linked site , that's just for info. , can be bought at most any marine supply store (West Marine , etc.) . 3M makes good stuff , dependable and has the reputation to back it , just sayin ...
Sounds like a good product. Just hope
it “keeps” for a reasonable period of time. I wouldn’t buy more than is needed for maybe 6 months. I have done patching with vinylester resin on vinylester/Kevlar, and while the patches were great, the resin set up in the clean glass bottle I bought it in. Which is just what one expects from vinylester or polyester that comes already promoted.
The fact that 3M puts in a microbubble filler means easy sanding.
Clean them and sand them lightly
Use two part epoxy, (you get the twin tubes in any hardware for less then $5).
Put it on with a throw away brush. Immediately tape a piece of clear flexible plastic, (like a loose leave page protector) over it.
The next day peel the plastic off, and if you did a good job there should be no or very little sanding.
If it is not smooth, or if it is indented sand it and repeat the process.
Get a good automotive spray paint to match the original gel coat and give it a coat or two and you should be good to go.
On my first QCC, I dropped it off the roof of the truck, and took the Gel coat off. Steve from QCC walked me through the process and since then I have used it many many times on different boats for small gel coat and skin coat repairs.
the 3M is two part …
..... part A , is about the consistency of thick peanut butter (call it a paste) and you use a narrow blade putty knife to scoop about a golfball size amount out of the can .
Wipe the part A onto a mixing board .
Part B , is a cream catalyst in a squeeze tube (blue color) , use about a 5/8"-3/4" line squeezed out onto the part A .
Mash and mix the A and B together with the putty knife until the blue mixes with the white into a uniform colour .
You now have about 10 mins. at room temp. to spread it into the repair area and rough fair with the putty knife .
On hot boat (like in Sun during summer) , and higher air temps. , you got about 4 mins. to place the mix into repair area ... and you can be sanding it in 10 w/o problems .
As long as your prep. work is sterilized (acetone wipe) and clean , this stuffs sticks and stays stuck ... and can be left exposed for years and years w/o any change except surface color darkens some (ie., dirt) .
Always clean your putty knife off with acetone wipe and quick sanding (if hardened on knife) between mixings ... don't want any cream catalyst from the knife to accidently get into the part A can when going in to get another scoop out .
Use a 6" drywall knife to scrape clean your mixing board before the batch just mixed sets up on the board . Sometimes acetone wipe the board and quick sand it too . The idea is to keep your mixing board clean for each new batch of mix .
You can use this same 6" knife to hold some of what you just mixed (left hand my case) , and take what you need off the 6" knife with the narrow putty knife (right hand) . Same as if you held the mixing board in one hand and the applying knife in the other .
Also this stuff does an excellent job of re-building the last 1/4"-3/8" detail of sharp chine edges that have been damaged (impact/nicked out) .
Sounds like one of the few practical
vinylester repair products for back yard consumer use.
for backyard gelcoating …
..... this little sprayer does an OK job .
I suggest adding 10%-15% Styrene by volume to the mixed gelcoat so it atomizes and sprays well . Acetone evaporates too quickly .
Room temp. is about the best temp. for spraying gelcoat .
4-5 thin coats of gelcoat . Proper gelcoat sanding , buffing , and polishing can leave an almost invisible repair if wanted .
I like to spray gelcoat because it's a hard tough finish surface ... as opposed to any paint which just scratches off . The gelcoat , no matter how good or poor of job you did (to the eye) , is hard and tough and doesn't scratch off .
I’m guessing that with the glass bubble filler this sets up white rather than clear. I used to work in the 3M lab that developed the bubbles. We made lots of stuff out of it.
the 3M Marine Premium Filler …
… the paste/dough (part A) in the can is an off white . The cream catalyst is deep blue .
Depending on the amount of catalyst used , the mix has a light bluish tint to it , but for the most part it sets up looking off-white (a yelowish blue white) .
This is a filling fairing compound (very sticky paste/dough) , not a resin (syrup) .