Another Devcon 2 Question

[Gambler250ProXS]

I'm new to painting crankbaits but not new to airbrush painting (did T-shirts starting in 1965). I read where some painters weigh out the epoxy to make sure both parts are equal so I started doing it. I've noticed that there's more epoxy left in the bottle than there is resin in its bottle, I'm guessing the epoxy is heavier than the resin but to look at the mixing cup they look equal and I don't have a problem with how the top coat comes out. Am I doing this right?

[nedyarb]

I weigh my epoxy also. I use bob smith which is similar to d2t. With a new bottle the epoxy weighs 320 grams and the hardener weighs 260 grams. So I mix 16 grams epoxy with 13 grams hardener to coat two lures! Works for me.

[RayburnGuy]

D2T and Bob Smith epoxies are both designed to be mixed by volume. Not weight. Some folks, like Nedyarb, have figured out the different weights of epoxy and hardener for the amounts they normally use. They can then use a scale to get the exact amount each time.

 

If you want to do it this way just measure out equal amounts of epoxy and hardener, in an amount that you normally use, into separate containers and weigh them. The graduated cups like they bring your pills in at the hospital work great for this. You can get them at most pharmacies.

 

good luck and welcome to TU,

Ben

[EdL]

Like RayburnGuy says most epoxies are mixed by volume of equal parts resin and hardener.  The resin has a property called density as well as the hardener.  Density is defined in science as unit mass per unit volume.  For our purposes mass is close to weight. (no doubt there will be a scientist who will call me out on this). So if you can figure out the weight of resin of say a full bottle of resin and the weight of a full bottle of hardener you can then use weight.  Just use the ratio of the weights like Nedyarb.  One thing to keep in mind is that if you switch brands of epoxy best check the weights of full bottles of the resin/hardeners your using.  There may be differences.  I don't use weight as its just easy enough to mix by volume and if I spill some of the stuff (its part of MY work process though not required by others) on a scale then I'm going to have to clean up my scale too.   Also if you want to mix batches by weight then you need to have a reasonably accurate scale. By accurate it just needs to have enough resolution (how many digits or marks) so you can compare the two (resin and hardener).   I tell young kids to pay attention in science class as it really does have some information you can use after all.

[Richard Prager]

I use BSI and all I do it warm up the bottles a tad and do an 8 count of each. I get 2 baits out of it and toss the brush. If its a larger bait, I use a 5 count and just do the one. I think the BSI and D2T are pretty forgiving with measurement (as opposed to something like e-tex)and I'm more concerned with temperature and mixing. Since i am now working indoors in the AC I have almost 100% success rate with epoxying. I'm probably the only one that does this but it works for me. Now, I just need to learn how to paint!

[mark poulson]

I mix D2T by eye, by squeezing out the same amount of each into a solo cup.

I've found that the exact mix isn't as important as mixing the two parts thoroughly.  It is a little forgiving in terms of exact ratios.

But it does have to be mixed well, or you'll wind up with spots that don't set up, so you'll have to recoat the bait.

Edited July 18, 2013 by mark poulson

[Vodkaman]

This may be seen as nit picking, but you need to subtract the weight of the containers before figuring out the weight ratio.

 

Many of the products that I have used in the past have quoted the ratios in the small print, or you may be able to find the information on-line. I too prefer to use weights for measuring, but lately I switched over to syringes.

 

Dave

[Travis]

These products are made for the most part for use by the general public and in doing so are just squirt/dump until it looks about the same and one is off an running.  The failure of these products comes down to guys just not mixing the product.   

[mark poulson]

Dave,

When I used to use 2 part epoxy for a top coat, I switched to using Flexcoat 3mm syringes, and never had a bad batch after that.

 

Travis,

You hit the nail on the head.  They build a lot of "forgiveness" in their homeowner products, to avoid high failure rates that would kill sales.

[Gambler250ProXS]

Thanks a lot for all the responses and good advise! I appreciate it very much.

Rick

[Kris]

Been using D2T since I started painting.  I just squeeze out lines of equal length and then mix.  Haven't had a problem with this method yet. 

[carpholeo]

I use  a 10 g epoxy  to 8 g  hardner ratio with D2t