acetone for thinning polyester resin?

[pW2]

a couple of friends are making a small sailing/motor ridgid tender. They use acetone for thinning thick resin, they say that it evaporates before the resin cures. They don't use styrene as a thinner because it upsets the composition of the resin. It's a good few years since I did any serious resin work, can somone bring me up to date please.

 

[nimbusgb]

In my experience just having acetone on a brush I used was enough to stop the stuff setting!

 

[GrahamM376]

In my experience just having acetone on a brush I used was enough to stop the stuff setting!

+1

Good for cleaning brushes and rollers but not good for resin. Can't understand what they're using, most resins already have styrene in the mix.

 

[PCUK]

I understood that adding acetone would seriously reduce the strength of the lay-up.

 

[Marine Reflections]

I understood that adding acetone would seriously reduce the strength of the lay-up.

+1

I think they have it the wrong way around.

 

[boatbuilder]

Styrene is the only thinners for polyester resin, do not use acetone, it seriosly compromises the finished layup.

 

[nigelmercier]

Styrene is the only thinners for polyester resin, do not use acetone, it seriosly compromises the finished layup.

+1

 

[jamesbell]

Yes you can.

http://www.ehow.co.uk/how_5869845_thin-polyester-fiberglass-resin-acetone.html

 

[Marine Reflections]

Link does not work.
Yes you can thin using acetone, you can thin it with lemonade if you want, just don't expect decent results.

Edit: link now works

 

[Keith 66]

When fibreglassing you do not normally ever need to thin the resin with acetone or anything else for that matter. What you do need is a good paddlewheel roller to consolidate the wet mat after a few minutes & roll the air bubbles out.
Acetone is for cleaning brushes & rollers & one of the primary causes of poor cure & osmosis is failure to knock out brushes or rollers & contamination of the laminate by dirty acetone.

 

[jamesbell]

In the link I provided, it talks about thinning resin when applying to wood, so it soaks into the wood better but for general laminating, ie: fibreglass onto fibreglass, I would not thin the resin.

 

[gjgm]

a couple of friends are making a small sailing/motor ridgid tender. They use acetone for thinning thick resin, they say that it evaporates before the resin cures. They don't use styrene as a thinner because it upsets the composition of the resin. It's a good few years since I did any serious resin work, can somone bring me up to date please.

The only reasons I can see for the resin being thick is that it is very cold, in which case it is going to taker forever to set, or it has started to set, in which case throw it away and mix smaller quantities.