Mixing Gelcoat with Topcoat

I think you'll find that topcoat is gelcoat but with wax added to facilitate it's surface curing. Otherwise it stays "sticky"
If you mix them, you will have wax in your mix so it will be a topcoat only then. Topcoat may also have styrene added to thin it slightly for "painting" on the surface.
 
Thanks very much for replying, would I be right in thinking then that once I have re laid the deck I use the gelcoat on top of that!!??
 
greeny said:
I think you'll find that topcoat is gelcoat but with wax added to facilitate it's surface curing. Otherwise it stays "sticky"
If you mix them, you will have wax in your mix so it will be a topcoat only then. Topcoat may also have styrene added to thin it slightly for "painting" on the surface.
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Thanks very much for that advice, I'm hoping you know a little bit more, once I have re laid the deck then the gelcoat is on top?
 
Yes the gelcoat is the top layer. It's what you see when the job is finished.

I'm not an expert so at the risk of others jumping in and telling me I'm wrong, here goes;-
Topcoat is gelcoat with wax added. The wax is to exclude the air from the top layer and allow it to cure. The top surface will remain sticky and not cure if air is not excluded. There are other ways of doing this with special films but wax is the most usual method. (you could spray pva or use a film layer).
First you do the repair in grp. Then you apply the gelcoat. For smaller repairs I usually apply one thick coat of topcoat (gelcoat including the wax ). The wax rises to the surface, seals the surface from air and allows it to fully cure. Then I rub it back with wet and dry paper to give the final finish with polishing.
If you just apply neat gelcoat at this stage, the surface will not cure and will remain tacky.
From your post it seems you are doing a much bigger area than just a repair. " once I have re laid the deck "
If this is the case, I won't try to advise you, as there are far more experienced people on these forums who can help you.
You may need to apply the gelcoat in several layers and will need to be sure what you're using and in what order. For example if you use wax in the lower layer the next layer will not adhere/bond for obvious reasons.
The internet is also your friend here. Some of the resin, gelcoat suppliers have excellent informational pages that will guide you especially if you are doing larger repairs.
East Coast Fibreglass Supplies
Instruction manuals, book, videos & workshops - WEST SYSTEM Epoxy
Just a couple of links that may help you. Many others online.
 
greeny said:
Yes the gelcoat is the top layer. It's what you see when the job is finished.

I'm not an expert so at the risk of others jumping in and telling me I'm wrong, here goes;-
Topcoat is gelcoat with wax added. The wax is to exclude the air from the top layer and allow it to cure. The top surface will remain sticky and not cure if air is not excluded. There are other ways of doing this with special films but wax is the most usual method. (you could spray pva or use a film layer).
First you do the repair in grp. Then you apply the gelcoat. For smaller repairs I usually apply one thick coat of topcoat (gelcoat including the wax ). The wax rises to the surface, seals the surface from air and allows it to fully cure. Then I rub it back with wet and dry paper to give the final finish with polishing.
If you just apply neat gelcoat at this stage, the surface will not cure and will remain tacky.
From your post it seems you are doing a much bigger area than just a repair. " once I have re laid the deck "
If this is the case, I won't try to advise you, as there are far more experienced people on these forums who can help you.
You may need to apply the gelcoat in several layers and will need to be sure what you're using and in what order. For example if you use wax in the lower layer the next layer will not adhere/bond for obvious reasons.
The internet is also your friend here. Some of the resin, gelcoat suppliers have excellent informational pages that will guide you especially if you are doing larger repairs.
East Coast Fibreglass Supplies
Instruction manuals, book, videos & workshops - WEST SYSTEM Epoxy
Just a couple of links that may help you. Many others online.
Click to expand...
Yes I am doing a large area, a small deck on a CJR 14ft Cathedral hull I have just had from a friend but the deck was very flimsy and although being 65 I am the type of bloke who likes to have things right, so! you may not want to advise me but the truth is you have been a massive, massive help to me with great advice as I am writing this I have opened another page and the video's on the site is fantastic because what was in my mind doesn't bear thinking, Thank you so much, Cheers now. Stay Safe
 
Jay Jay said:
Yes I am doing a large area, a small deck on a CJR 14ft Cathedral hull I have just had from a friend but the deck was very flimsy and although being 65 I am the type of bloke who likes to have things right, so! you may not want to advise me but the truth is you have been a massive, massive help to me with great advice as I am writing this I have opened another page and the video's on the site is fantastic because what was in my mind doesn't bear thinking, Thank you so much, Cheers now. Stay Safe
Click to expand...
Thanks Jay Jay. I appreciate your message. I've done a lot of smaller repairs, scratches, small prangs etc but never done a large area or structural repairs. Thats why I was reluctant to maybe give you any bum advice on the larger stuff. I'm actually surprised that no one else has come in here to help you as normally there are lots of good guys out there with better knowledge than myself.
Sounds like you've got a decent sized job on there so good luck, I'm sure it will work out ok in the end. Don't underestimate the amount of work though. Getting good results takes time.
 
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