Resin to hardener Ratio

[danstroup284]

bought some glass and resin for my project. But I think that the person that helped me was a little high. She said 1 ounce of hardener to 1 gallon of resin. Test cup is still spongy after 4 hours. Think it is safe to kick it up to 2 oz per gallon to obtain a decent set time? Totally a newbie when it comes to glass, so any input would be welcome!

Dan

 

[reelfishin]

Re: Resin to hardener Ratio

An ounce to a gallon sounds like it's about right, I never really checked to see how much hardener came with the cans I use, but it's not more than an ounce and I've never run out. You do have to mix it well though. I found that adding only a very slight additional amount of hardener speeds the hardening time greatly, doubling it may be too much. I had a rep tell me that with any MEK hardener, the quantity only makes a difference in dry time, and even the slightest amount of hardener will eventually react and harden. I was told that after I complained about how fast their product was setting up, he told me to use even less hardener and it does work better. I went through a gallon of resin and had almost a quarter of the little tube left over, the result was that it took almost to the next day for the work to harden completely, but it seemed to bond better with less distortion to the surrounding fiberglass.

Call the manufacturer, they will be able to tell you what is best with their product. If not check for info on their website. Most auto parts store resin even comes with the required hardener for that amount of resin.

 

[fbnewbie]

Re: Resin to hardener Ratio

It varies by manufacturer

I don't know about ploy resin , but regular epoxy is usually measured in ratios and I use a 2 to 1 part mix. I have seen some at 4 to 1 and 5 to 1 , but never heard of a 1 oz to 1 gallon ratio.

Using the correct ratio is very important

 

[Big Dog Daddy]

Re: Resin to hardener Ratio

I assume you are talking about poly and not epoxy, if it's poly then yes the mix ratio can vary depending on the temp of the environment you are in. I normally use 4 drops of MEKP per oz of resin, if it is cold outside I would add a few more drops. Also I try to mix up 4 to 8 oz at a time for small projects that way if I mix it too hot I don't waste a whole gallon. Hope this help, I'm no expert by any means, just learned from experimenting with it and help of others.

 

[jaurora]

Re: Resin to hardener Ratio

I just finished redoing my floor in my boat. It is a 19' CC and I went through 5 gallons of poly resin. The way the package said to mix it was 14 drops per oz of resin. I figured I would me there all day measuring so I bought a small measuring cup for 50 cents at home depot, measured out 100 drops so I wouldent have to count all the time.

 

[drJ]

Re: Resin to hardener Ratio

my brand says 1 oz per gallon but double in temps less than 77 degress

 

[Robj]

Re: Resin to hardener Ratio

I just finished a stringer/floor/transom replacement. Being north of the border, I can tell you what I used, but it is in metric.

At about 70 degrees F, use about 7-8 ml's of hardener to one litre of resin. If it is a little warmer, maybe use 6-7 mls. Do not work in direct sunlight or it will harden even faster, and make sure you use at least 6 ml's per litre, anything less will cause problems.

Good luck and have a great day,

Rob.

 

[danstroup284]

Re: Resin to hardener Ratio

Ended up with a ratio of 13 cc to 1 quart. This ratio was used to prep the wood before installing it. Pretty quick (20 min) gel time. Probably gonna go back to 10 cc to 1 quart for the actual glassing. Thanks for all of the input.

Oh, and I did find out that 25 cc to 1 quart was way too hot! Pretty cool to see though!

Dan

 

[Robj]

Re: Resin to hardener Ratio

I think 1 quart = 946 ml, or 0.946 litres for which I would about 7 ml or cc (same thing) at a temperature of about 74 deg F. Make sure you use at least 6 cc per quart regardless.

Have a great day,

Rob.

 

[ondarvr]

Re: Resin to hardener Ratio

You should go with no less than 1% catalyst on resin, which is 1.28 oz's per gallon, 1.25% to 1.5% is better. If not enough catalyst is used the resin will eventually get hard, but it will not be a good complete cure, so it won't be as strong as it should be. If you need more time, mix less resin at one time, only enough to use up before it does get hard, don't under catalyze it. Retail out lets that tell you to use less, do it because they buy a resin with a gel time that's too short for an inexperianced person to use on a large project.