resin mixing

[Electric Comet]

do you measure and mix by volume or weight

i think i will do the ratio by weight seems more accurate to me in case of volume differences due to ambient temperatures

[Lew Hodgett]

----------------------------------------------------------- What are you mixing?

Lew

[tdacon]

I've been using West Systems epoxy for twenty-five years or so, 105 resin and usually 205 or 206 hardener, and mixing 5:1 by volume throughout that whole period without any troubles at all. Their web site says 5:1 for either weight or volume, so apparently they're very close to the same density.

On the other hand, to mix 105 resin with 207 or 209 hardener, they say 3:1 for volume and 3.5:1 for weight, so they must differ in density enough for it to matter.

I used to use their calibrated pumps, but stopped a long time ago because the pumps dribble a bit as air pressure changes, and probably on account of capillary action, and the cleanup got kind of messy. So now I just use pairs of small graduated cups for measurement. I'll take a fine-point sharpie pen and mark the graduations on the two cups so that I can eyeball the measurement accurately.

You should consult the manufacturer's instructions for whatever system of epoxy you use, and go by their recommendations.

Tom

[J. Clarke]

Do you have the correct information to mix by weight?

The "right" way to do it is usually with a purpose-made ratio pump.

[Sonny]

If I'm not mistaken, your local drug store should have 5cc, 10cc and 30cc s yringes available. If not your drug store, try purchasing syringes from a medical supply outlet. You can eject the air, from the cylinder, before use, to prevent that air issue, as with the calibrated pumps. *I've never used their pumps.... I suppose their pumps are, essentally, a syringe-type mechanism? **Medical syringes may be too small for your applications.

Syringe use: Pull the plunger out, to fill from the large end/opening. C leanup, for reuse, is fairly easy, too, with the plunger/piston removed.... just make sure you clean/clean around, well, the rubber gasket on the plun ger/piston.

Sonny

[Leon]

What does does the label say?

Equal parts? Volume

Most consumers aren't chemists and probably do not have scales accurate enough. Unless the label specifies weight it might be wrong to assume that equal volume of both parts weigh the same.

[Electric Comet]

recall the question was do you mix by volume or weight

not should i etc

so the label does not say leon always mixes by volume

so only chemists can have accurate scales but what of the chemist that is also a consumer

BTY i have a sub $20 scale that's accurate enough

that is a true statement

[Electric Comet]

is that what you do if so then you mix by volume

[Electric Comet]

not sure what the name of this stuff is it is specific for doing bar tops and table tops

mixing well is important to make sure the polymerization proceeds evenly and consistently

maybe 207/209 are a little hotter catalyst

pumps are over complicated

makes sense to mark it for good visibility

i have but will review once i get to pouring time

although i will do later in the day when it is cooler so it does not fire off too quick

[Lew Hodgett]

---------------------------------------------------- Bar top is a totally different animal than laminating epoxy.

Defer to the manufacturer's instructions.

If you don't have one, get a JiffyMixer.

Designed specifically for mixing resins.

Viscosity is not your friend when mixing.

Temperature is not your friend. Stay between 65F-75F.

Have fun.

Lew

[Leon]

So you want to hear both right and wrong answers... Got'cha

I bet you are right.

If you are going to quote me please use everything I said.

Most consumers aren't chemists and probably do not have scales accurate enough.

Won't work.

How do you know this is true?

Now see how this all got confusing when you cut my sentence and used the remainder here?

So for those wondering, like me? Do you think you are smarter than every one here. Most here are just trying to help anyone that is asking questions. If the answer makes you go DUH! why didn't I think of that, just say DOH, why didn't I think of that. Instead of being an ass.

[Electric Comet]

so much drama the question was simply when you mix your resin do you weigh it or measure it by volume

keyword is you what do you do not what should i do

[Leon]

Actually you said, "do you measure and mix by volume or weight".

It sounded like you were solicitation a correct answer vs, a personal preferred method. Rewording your sentence, as you have done above, seems to steer more toward asking a preference, especially when you added "your" in the revision of the first question vs. you. The fact that you did change the words, your for you, solidifies that fact.

Anyway the way you ask questions may be different because of where you are from vs. where I am from. Either way I was not the only one confused by exactly what you wanted to know, a personal opinion or the correct way.

keyword is you what do you do not what should I do.

What? Should there have been a few commas in there?

I "was" the worlds worse at proof reading. You may be now.

[J. Clarke]

Why do you care so much what other people do?

[Electric Comet]

you sure get worked up about nothing did you ever answer i lost track in all the other stuff

[John McCoy]

Electric Comet wrote in news:mq2vol$ge1$2 @dont-email.me:

The manufacturer will tell you that you should mix by weight if you want to be precise.

That said, everyone I know mixes by volume, and all the manufacturers sell pumps/syringes/cups/whatever to let you mix by volume.

As Mike said, it isn't something that's critical for almost any application you're likely to do (since most of us are not making composites for NASA). If you're a little heavy on the catalyst, it'll harden faster (possibly before you get it out of the mixing pot, which tends to be annoying). If you're a little light, it'll take longer to harden and will be weaker (and possibly will just stay a gooey mess if you're way light).

John

[Leon]

Because he does not know the proper way to do things but believes he will recognize the correct way when and if he reads it.

[Leon]

You missed it when you were busy calling the kettle black.

[Leon]

Strange enough, a small mesquite outlet near the Texas hill country, which went up in the fires a few years ago had beautiful mesquite objects and lumber for sale.

The owner indicated that they use an epoxy resin coating to give the deep coating on some pieces.

The use of a canister fuel torch was used on the applied resin during cure time to make the bubbles dissipate. He said that it was an acquired talent.

[dadiOH]

It's pretty easy actually, pass the torch over it slowly enough to heat the air in the bubbles thereby expanding it and popping the bubbles but not so slowly that the epoxy catches fire :)