Hi, my gelcoat is almost over and Easycomposites is not shipping until jan.
Is it possible to make a do-it-yourself gelcoat?
How?

Thanks

+x

 

Massimiliano - 12/26/2020 10:45:43 PM

Hi, my gelcoat is almost over and Easycomposites is not shipping until jan.
Is it possible to make a do-it-yourself gelcoat?
How?

Thanks

Anyone?

It is possible, but you need the right blend of additives. You can make do with just cab-o-sil (fumed silica), but it doesn't really make a gelcoat. 

+x

 

Hanaldo - 12/29/2020 10:31:39 PM

It is possible, but you need the right blend of additives. You can make do with just cab-o-sil (fumed silica), but it doesn't really make a gelcoat. 

Do you have a list of such additives?
Epoxy tooling gelcoat, besides the fact the I am out of stock at the moment, is really expensive and sometimes I need something for a one off mould that will be discarded after the first use.

Fumed silica is virtually essential to make a thixotropic paste. Calcium carbonate will increase the hardness and gloss retention. Graphite powder will give you a nice slick dark grey/black surface. Aluminium powder will help with temperature distribution. There's quite a few others, but those are the ones I would probably start with.

My advice - it is cheaper and easier to buy the proper stuff. By the time you've bought all these additives, you won't be saving any money. And then to blend gelcoats becomes quite a time consuming task, and to get it the same every time means keeping records of your recipes. Above all, it just doesn't work as well. The porosity is higher, so the gelcoat is weaker and you can end up with quite high surface porosity. It won't ever polish up as nicely, the gloss retention and polish-ability just isn't as good as the proper stuff. 

For one off stuff, I would maybe think about using mostly fumed silica with maybe some graphite powder or black pigment just to give it some colour. But you will find it won't be a lot cheaper than proper tooling gelcoat.