Isophthalic Polyester Resin WTB

I have used up my first gallon of Isophthalic Polyester Resin #90 from Fibreglast.
It’s so expensive that I am looking for another sorce of the same type resin for less money in the US. I’m using the resin for mold making so my next question is.
Do I need to use isophthalic resin or could I just use any regular polyester resin for mold making?

Out of curiosity: What are you paying?

ISO is OK, but for mold making shrinkage and heat resistance is what counts. A vinylester would be nice, or a tooling resin (which usually have polymers in it which counterbalance shrinkage).

If you only use room temperature moulding, you could get away with ortho resins. Build up your mould very slowly, to prevent shrinkage and warping.

The stuff from fibreglast is $65 a gallon

So vinylester is better than the ISO for mold making?
Can VE resin be used with PE surface coat?

Thank you for your help, you are always one of the first to answer my questions.

Reasonable expensive.

To answer your questions: yes, and yes.

First lesson in composites stay away from fibreglast unless you have no choice they are way overpriced.

http://www.uscomposites.com/polyesters.html

Yes Im starting to see that, I wonder how they can get such money for their products.

Thanks for the link those are some good prices. Do they ship quickly?

Which resin smells the worst PE or VE?
I work in my garage attached to the house and the fumes are horrible with PE. The smell is in the house for at least a couple days. Plus I worry about my family and pets with the fumes. Are they dangerous?

Same smell. About harm: no consistent data, but why take the risk?

Go to fiberglass coatings Inc. In Dania beach. I pay $150 for 5 gallons of ISO. $175 for VE.

It’s very harmful. You should work in a vented area for sure.

Thanks for the help.
I decided to buy some VE and give it a try. Does it work any differently than the PE I have used? Does it work well with fiberglass mat for mold making?

It does not work differently, and can be used with mat.

it will require a less reactive catalyst.
similar to use, so shouldnt be any suprises.

So the Methyl Ethyl Ketone Peroxide(MEKP) I’ve been using with the PE won’t work?

MEKP works just fine with VE resin. However, you should always check the datasheet for the resin you are using and do a cup test to confirm. Sometimes CHP is a good choice to reduce the amount of foaming when the resin is catalyzed and to reduce peak exotherm.

Hi Extreme,

We ship out of Ventura, CA. Here’s what you’re looking for;
http://shop.fiberglasshawaii.com/resin/polyester_resin/iso/rpis-iso_resin
http://shop.fiberglasshawaii.com/resin/polyester_resin/vinyl_ester/rpveri35015-vinyl_ester_resin_33350-15_hydrex
Good luck and let us know if we can help you out with materials.