Acetone and Reducer...Difference?

Hi folks,

I am putting a fiberglass resin on the floats for my Dehavilland Beaver to waterproof them and also about to lay a woven mat on the bottom of the floats for scuffs on the beach etc... I have already brushed on the resin and WOW!....sealed up everything and am very happy with my finish etc... (have done two thin coats by brush)...I was told by the Hobby Store to cut the resin with about 10% Acetone to thin the resin for applying the woven fiberglass mat to the bottom of the floats. They said it would give a better finish.... my questions are these.... I have a gallon of Reducer for enamel paint (automotive grade)....is that the same as acetone?....Will it work as a good substitute? And lastly....do you really think I should use a 'thinner' as I have a pretty good feeling about the way I am presently working with this stuff...maybe I should just continue on and say to hell with the advice of the hobby shop and use the same recipe over the woven material?...Thanks in advance...Jim

Reply to
Jim & Lil
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NO. Enamel reducer is a cocktail of chemicals used to reduce the viscosity of enamel paint without affecting its properties.

Reply to
Paul McIntosh

Resin is a rather generic term. What type of resin is it? Generally it will be either polyester resin or epoxy resin. If it is epoxy resin, use alcohol to reduce it. Not rubbing alcohol which contains water, but pure methyl or ethyl alcohol (denatured alcohol).

In some cases acetone is the catalyst for polyester resin and will cause problems if used as a reducer.

Some polyester resin has a wax in it that will come to the surface when cured. It will need to be sanded to remove the wax before the next coat is applied or you may get separation between the coats. Generally, when applying more than one coat, epoxy resin is preferable.

As Paul said, don't try the other ruducer you already have.

Reply to
JR

Methyl ethyl ketone peroxide is the standard catalyst for polyester resins (don't EVER get it in your eyes btw - read the warnings and wear protective eyewear! This is NOT paranoia.). Methyl ethyl ketone (MEK) or acetone won't catalyze polyester resin.

Ideally, for laminating you should use a resin system with a viscosity and wetting ability that does not require solvents to thin the system. Though many resins appear to be more viscous than intuition would lead one to believe would be effective, they will still wet out the cloth and substrate well.

When making multiple layered layups with polyester resin, you should get unwaxed resin, which is available from fiberglass supply houses. In which case if you're there, and don't want to use epoxy, you might consider vinyl ester resin which sits between polyester resin and epoxy for mechanical properties.

Mike D

Reply to
M Dennett

Reply to
Jim & Lil

The two different polyester resins are generically know as laminating resin and finishing resin. The laminating resin does not have the wax in it so it will accept fresh resin on top and give proper adhesion. The finishing resin has a wax in it that rises to the surface and helps the resin lay flatter so less sanding and filling is needed. I refinished my Mercury sailboat several times while owned it. The boat shop made sure I got all the right stuff and gave great instructions.

Reply to
Paul McIntosh

Acetone is the same as "polyester resin cleaning solvent" and will work to thin the resin, but will hamper the curing. We pay way too much sometimes for ordinary, inexpensive chemicals in small containers with fancy names. It pays to look at the small print to see what it contains, then look elsewhere for that chemical. This can apply to a lot of household stuff as well as over-the-counter drugs. Another example is "contact cement cleaning solvent" which is nothing more than laquer thinner (or toluene). Dan

Reply to
Dan Thomas

It is highly unlikely that you will get anything with toluene in it any more. That stuff is REAL nasty. Xylene is much safer to use.

Reply to
Paul McIntosh

I dunno 'bout that . . . got a dozen or so cans of the stuff on the stock shelf.

It looks an awful lot like

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Fred McClellan the dash plumber at mindspring dot com

Reply to
Fred McClellan

Saw it for sale today at Ace Hardware.

Reply to
jeboba

I guess I was mistaken when the EPA declared them class 1 carcinogens about

15 years ago that they would be withdrawn. We switched over completely to xylene. It is 5000 times less "nasty" than toluene. In other words, air saturations 5000 times stronger are less toxic than toluene.
Reply to
Paul McIntosh

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