I need to paint on a few layers of gelcoat to cover up some marine filler. What is the best way to apply this (I cannot spry) I was thinking of using some of those disposable foam rollers.
gelcoat over marine filler?
- Thread starter colin hunter 335
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Disposable power sprayer
Some hardware stores sell a disposable spray unit- clear glass jar with a screw on propellant canister. Mix gel coat in jar, attach propellant, spray away. Works great. Just did 8 ft. of toe rail on my C22 with great results.
Some hardware stores sell a disposable spray unit- clear glass jar with a screw on propellant canister. Mix gel coat in jar, attach propellant, spray away. Works great. Just did 8 ft. of toe rail on my C22 with great results.
What kind of finish do you want?
If you do not care about the finish being smooth then you can roll on. There are aerosol spray bottles available to puy the gelcoat in for spraying. Jamestown Marine Supply handles them I believe. If you roll make sure you add some thinner for a smoother finish and that it is air-dry gel or you will have to cover with waxpaper or Saran Wrap to get it to cure.
If you do not care about the finish being smooth then you can roll on. There are aerosol spray bottles available to puy the gelcoat in for spraying. Jamestown Marine Supply handles them I believe. If you roll make sure you add some thinner for a smoother finish and that it is air-dry gel or you will have to cover with waxpaper or Saran Wrap to get it to cure.
What kind of thinner? acetone
I have gelcoat from Hunter I assume it is air dry. What do you thin the gelcoat with and then do you add hardener to the new thinner volume or to the original gelcoat volume?
I have gelcoat from Hunter I assume it is air dry. What do you thin the gelcoat with and then do you add hardener to the new thinner volume or to the original gelcoat volume?
gel coat application
I found the Preval sprayer (West Marine has them) to be the best way to apply gelcoat over a larger area. When I tried to brush it I got ridges in the gelcoat. Whatever you do to put it on, gelcoat needs to be wetsanded afterwards with increasingly finer grits to get a shiney finish like the original. Its not really that hard to do - go 250, 600, 1200 and then 3M finessit II or similar rubbing/buffing compound. I thinned gelcoat with Acetone, but I know for a fact that some gelcoat manufactuers (Spectrum Color for example) are recommending the use of Styrene Monomer instead. The amount of catalyst should probably be related to the original volume of gelcoat, but only was thinned 20% (the recommended max) and catalyst amounts are sort of a guessing game with the weather anyway. Note that gelcoat either has to be covered or have a wax additive to protect it from air while it cures. I used the wax additive. For a small area, if you can't spray, you might just dob some on with a brush and then wet sand it out. Here is a link to Spectrum's gelcoating instructions:
I found the Preval sprayer (West Marine has them) to be the best way to apply gelcoat over a larger area. When I tried to brush it I got ridges in the gelcoat. Whatever you do to put it on, gelcoat needs to be wetsanded afterwards with increasingly finer grits to get a shiney finish like the original. Its not really that hard to do - go 250, 600, 1200 and then 3M finessit II or similar rubbing/buffing compound. I thinned gelcoat with Acetone, but I know for a fact that some gelcoat manufactuers (Spectrum Color for example) are recommending the use of Styrene Monomer instead. The amount of catalyst should probably be related to the original volume of gelcoat, but only was thinned 20% (the recommended max) and catalyst amounts are sort of a guessing game with the weather anyway. Note that gelcoat either has to be covered or have a wax additive to protect it from air while it cures. I used the wax additive. For a small area, if you can't spray, you might just dob some on with a brush and then wet sand it out. Here is a link to Spectrum's gelcoating instructions:
Taylor - a question
When you sprayed on the gel coat with the wax additive did you do multiple layers/coats? How long in-between and did you have to sand each coat? The link you included made it seem as though you would have to sand every coat - or can you do multiple coats in a short time period? Reading this thread is giving me the courage to try using gel coat in a few small places on my boat.
When you sprayed on the gel coat with the wax additive did you do multiple layers/coats? How long in-between and did you have to sand each coat? The link you included made it seem as though you would have to sand every coat - or can you do multiple coats in a short time period? Reading this thread is giving me the courage to try using gel coat in a few small places on my boat.
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