epoxy question

I use West System 3 and it does not take any extra time to cure when I add color.But i do use a dedicated epoxy colorant.
Stan
 
I use Acraglass and the colorant sold for it and also can't tell any difference.I only use an extremly small ammount of colorant per glue up.I just barely touch my mix stick to the color before blending the epoxy.
 
If the colorant is made for the epoxy type you are using, it should not affect the cure time much or any. If you are using an adulterant, like model paint, regular paint colors, or some other type of dye, then it may seriously affect the curing.
 
I'm using T-88 , and the colorant was some pretty generic looking stuff from woodcraft.
I didn't use much but I suppose It still could have been too much. After 24hrs it could still be dented with a fingernail.
 
How did you mix your T-88 - by eye, by volume measure, or by scale?
How long did you mix it?
How old is the epoxy?
Those dyes at woodcraft are for dying wood, and will cause some problems when added to epoxy, but if it is just a tiny amount, it should still cure ( give it a day more). If it never gets hard, then I would suspect the resin is bad.
Also, when you say, " Dents with a fingernail", is it still sticky or just soft.Epoxy isn't steel, it isn't rock hard ( and you don't really want it that hard).It needs the plasticity to withstand stress and slight bending without failure. The full hardness on structural resins like T-88 doesn't develop for several days to a week or more.

The enemy of most epoxy is its shelf life. Most are only really good for 6 months.T-88 and some other high level resins ( Acraglas) have longer shelf life. The difference in most epoxy resins is the dilution amount.....yes the cheaper epoxies have a solvent added. Solvent free resins ( the higher grade ones) technically have an endless shelf life. The manufacturer of T-88 says to test it after a year, but if stored sealed tight,cool and dry, it lasts many years.
Conversely, many of the rapid set epoxies have a very short shelf life.Some of the stuff you buy in the bubble paks at the hardware store are out of date when you buy them.

The general rule is to store cool and dry, and allow to warm up to room temp before mixing. Cure at room temp. This is another good thing about T-88 as it can set as low as 35F.
The dry powdered dyes sold by K&G are superb for coloring resins.
 
I never use old epoxy for a knife. If it is not fresh within that week I use it for other projects that I wouldn't be upset if I had to reglue.

Having said that over the years I have experimented with different colorants Most oil based paints will work and model paint. But I have found some colorants I have used do extend the cure time but have yet to find one that effected the final hardening. After all it usually only takes a drop or two to get the color you are trying to achive. If is gets hard enough to sand and not gum the paper it probably is OK.
 
bladsmth said:
How did you mix your T-88 - by eye, by volume measure, or by scale?
How long did you mix it?
How old is the epoxy?
Those dyes at woodcraft are for dying wood, and will cause some problems when added to epoxy, but if it is just a tiny amount, it should still cure ( give it a day more). If it never gets hard, then I would suspect the resin is bad.
Also, when you say, " Dents with a fingernail", is it still sticky or just soft.Epoxy isn't steel, it isn't rock hard ( and you don't really want it that hard).It needs the plasticity to withstand stress and slight bending without failure. The full hardness on structural resins like T-88 doesn't develop for several days to a week or more.

The enemy of most epoxy is its shelf life. Most are only really good for 6 months.T-88 and some other high level resins ( Acraglas) have longer shelf life. The difference in most epoxy resins is the dilution amount.....yes the cheaper epoxies have a solvent added. Solvent free resins ( the higher grade ones) technically have an endless shelf life. The manufacturer of T-88 says to test it after a year, but if stored sealed tight,cool and dry, it lasts many years.
Conversely, many of the rapid set epoxies have a very short shelf life.Some of the stuff you buy in the bubble paks at the hardware store are out of date when you buy them.

The general rule is to store cool and dry, and allow to warm up to room temp before mixing. Cure at room temp. This is another good thing about T-88 as it can set as low as 35F.
The dry powdered dyes sold by K&G are superb for coloring resins.
Click to expand...

+1 on the K&G pigments. They work great. :thumbup:
 
well I checked the pigment and it's system three just like the epoxy. I bought the epoxy about 3 months ago, but I don't have a clue how old it is.
I measured by eye and mixed for about a minute.
It feels much better now, I wouldn't say it was sticky but definitely tacky.
I was under the impression epoxy was supposed to get rock hard after cured, Thanks for the info!
I'm thinking maybe I went light on the hardener.
 
System 3 is a little picky about mixture,I use one of the harbor frieght little gram scales and mix 2 parts resin to 1 part hardener.Works great.
Stan
 
Yes, system three ( really all epoxy) should be mixed exactly by the directions. Read them carefully, as different resins have different mix ratios. If measuring by weight, make sure the directions give weight mixing numbers as well as volume mixing. T-88 mixes one to one by volume, but mixes 1.00 to .83 by weight, as the resin is heavier than the hardener.A cheap gram scale can make a lot of chores more accurate.
 
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