Hi,

I was wondering what is the difference(s) between tooling gelcoat and "regular" gelcoat, vinylester or epoxy.

I tried to find some informations on the web, but did not see anything special. English is not my main language so I'm prolly missing some keywords... And since I'm curious, i wont sleep well until I know

 



 


    A $1000 electronic device will always protect a 10 cents fuse

This should help...

Thx Kev,

But I wanted to know what does make them different, in a chemical point of view.

Maybe I should have been more precise in my question.

 



 


    A $1000 electronic device will always protect a 10 cents fuse

Hi Joe,

I won't go into the actual low-level chemistry (especially because it's totally different between polyesters/vinylesters and epoxies) but essentially tooling gel-coats are very much the same family as regular gelcoats however the are engineered to prioritise certain properties (hardness, polishability and dimensional stability). This might not sound very different to a regular gel coats and in fact they're not but they will traditionally all include fillers (to improve their dimensional stability) whereas generally a gel coat that's designed for parts will not have fillers (because its appearance, either clarity or ability to accept a pigment) is very important. The hardness of a tooling gelcoat can also be higher because they're designed to be the surface for a rigid tool; this means that they don't need to be 'flexible' in the way that a gel coat designed for parts would need to be to prevent it from cracking if the part flexes.

The bottom line, in practical terms, is that tooling gel coats and regular gel coats are chemically similar but tooling gel coats can take advantage of the fact that they won't be flexed and don't need to be clear or easy to pigment. These distinctions mean they can be much better gel coats as a mould surface (harder and filled) in a way that a regular gel coat cannot.

I hope this helps,

Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Gelcoat usually referes to polyester group of resins. Tooling gelcoat cures to a much harder surface than regular gelcoat. Therefore it can be polished to a higher luster. I believe it is also more brittle but that is OK for a mold because you will not flex the mold, you will the part. Regular gecoat is meant for parts, it is less brittle. Both polyester gelcoats can be had in spraying or a thicker brushing form. Polyester is the cheapest resin. Epoxy is the most expensive . Its not really referred to as gelcoat but as a surface coat. It is not sprayed because of the vicosity and health danger. ( to the best of my knowledge any way)   

Hope this helps some what.

Fred 

Hi Fred,

Maybe product names and descriptions differ from region to region but as far as I'm aware, it's just as conventional to refer to an epoxy or vinylester 'gelcoat' as it is a polyester gelcoat. Of course polyester gelcoats are far more common in the wider composites industry because the bulk of what's getting made is still 'bucket and brush' polyester resin and glass so if someone just says 'gelcoat' out of context then my guess would be that they mean polyester but without asking it could certainly be vinylester or epoxy, particuarly if it's a tooling gelcoat (epoxy gelcoats for parts are very rare).

From a health point of view I think I'd rather spray epoxy than polyester but yes, epoxies are thicker and epoxy tooling gels are thicker yet and so would almost always be brushed or rollered.

--Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

We have gone a bit of topic but I use the EC Uni- Mould System and I spray the Tooling Gelcoat using a Gelcoat gun with a 6mm tip. I find it quicker and easier to get a uniform thickness especially on large moulds.

Hi Matt

Yes your right, gelcoat is kind of generic hear in Canadian snow country.

My concern with spraying epoxy is the sensitivity issue that epoxy has. I am sure polyester isn't good for you either but it doesn't have that same sensitivity danger. Once your body is sensified to epoxy, you can break out in all kinds of skin issues with just the slightest exposure. But if gloves are worn and common sense safety is observed it is safe.  

Fred