Hello there everyone. I bought a resin having the mixing ratio 100:2. I was wondering if using half I will use 50:1 or less 25:0,5 ? It is correct ?
Thank you !

It is polyester.

Ratio is a ratio, it doesn't change. 100 parts Part A to 2 parts Part B is the multiplier and can be applied to any number you like. It simply means for every 100 parts of resin you have, you need 2 parts of hardener. Eg. If you bought a 5kg kit and you were mixing up 4kg you would need 4000÷1.02, hence you would measure out 3921g of resin and 79g of hardener. If you needed to mix up 2kg you would need 2000÷1.02, hence 1961g of resin and 39g of hardener. You can use this for any amount of resin, but your ratio is always 100:2.

Thanks a lot ! So if I mix 50grams of resin I’ll use 49 A and 1 B

Matthieu Libeert
Founder MAT2 Composites X Sports
website: www.mat2composites.com

A rule of thumb I use with Poly or Vinyl is 5 cc MEKP per half liter. 10cc if using tooling gelcoat.

You really don’t need to be super accurate with poly or vinyl because they only need catalyst to speed up the cure rate. Poly will cure on its own without MEKP (in like 100 years).

If you mess up and your part is not curing move it to a hot room, and last ditch effort put it out in the sun.

Jason

I have always mixed catalyzed resins as 100g + 1ml for 1%, technically incorrect but bloody close, these resins adjustable % anyway and not a fixed ratio like other resins.

Also makes the calculation really easy and less risk of mix mistakes.

For 1% ratio 1kg of resin is 10ml of catalyst.

100g is1ml
5kg is 50ml

Using mls with squeeze type catalyst dispensers.