Epoxy Question

[Mike Cutler]

I've been building LOML an interior stained glass door, and I finally have gotten to the point where things need to be "glued up". Taking recent discussions to heart concerning the benefits of Epoxy as an adhesive, I decided that I would use Epoxy for this project.
I have the West System Three Epoxy Kit with the "intermediate" temperature catalyst. I also have the West Sytem metering pumps to measure out the resin and catalyst.
I epoxied some of the smaller parts to get a feel for the process, but I must be doing something wrong, or lack some type of fundamental understanding, because the epoxy is setting up fast. The pot life is supposed to be 25 minutes, but I'm not getting anywhere near that. I'm getting maybe 12-15 minutes.
I would like to use the epoxy to do the entire project, but I have 4 large M&T joints that have to be done, the door pulled into square, and the clamps set. There is no way I'll make it with this pot time.
I've measured the resin and catalyst components seperately, so I'm pretty certain that the ratio is correct. I know that there is another catalyst to extend the cure time of the epoxy, but I don't know if it extends the pot life. I've downloaded the epoxy manual from system three, but I must not be reading it correctly, because I'm not seeing the issue addressed. Can I mix another pot and keep going, or will the epoxy in the joint be setting up just as fast as the pot?
So folks, What am I missing here? any input would be appreciated. I'm initially pretty impressed with this product. I've played around with some scraps and like what I see. I'd like to use this for the entire door joinery, but I need to resolve this issue. TIA

[Bob Johnson2]

Epoxy hardens faster as temp increases, it heats quicker (chemical reaction) the thicker or deeper it is in your container. If you were to mix it for the required 2 minutes then pour it into a longer/larger container so that it was relitively thin it would take longer to harden. After mixing use something like a flat tin foil pan. The epoxy you've spread on your joint will NOT set as quick as that left in the pot due to it being much thinner. But don't walk away, it's not very forgiving.

[Mark Singer]

Mike,

large batches cure quickly. Also small paper cups seem to accelerate the speed. Maybe swith to 206 or 209 slow hardner....That will give you more time..I often have the same problem on working time. Try to phase your glue ups when possible.

[Richard Wolf]

If you cool it in the refrigerator first you will gain some pot life.

Richard

[Mike Cutler]

Ahhh... I see a couple of potentail problem areas.
1. I was mixing it in the System Three mixing cups, which are a tall paper tumbler shape.

2. I think it may be too hot in the shop for the process. It was probably about 85 deg. in there when I was doing this.
I'll try the "dispersion method" Bob. It may be that too much heat is being generated in the mixing cup, like you implied.
Richard I just put it in the 'fridge, and we'll give that a go tomorrow, thanks for that tip.
Mark. I'm going to try the "Decelerant" if it's still to fast. The glue up is set too go in stages, but that last glue up stage is the top and bottom section to both stiles, and that's the one that concerns me. The top is 9" wide and has two haunched M&T joint, and the bottom is a 17" wide piece that has 3 haunched sections. Each tenon size is 3" wide(along the stile) and 4" deep into the stile. Not complicated, just a lot of surface area, and alignment.

[Bob Smalser]

Also get a can of their slowest-cure hardener for warm-weather use.

http://www.fisheriessupply.com/onlin...P_Sort/Ntk/All

[Steve Coles]

I use the system three all the time and have had that be a problem. The only guesses I can come up with are:

1. Not mixed properly - be sure you have a uniform color
2. Too much hardner. you mention that you are using their metering pumps. I double check that you are getting the right ratio (2pts - resin 1pt - hardner)

[Frank Hagan]

One of the tricks we use in boat building is to have a "cool bath" for the epoxy ... mix it up, and put in a shallow pan, than put that pan in a larger one that has ice in it.

I think the term for it is "exothermic", meaning it will create heat as it cures. And heat makes it kick off faster, so you can very quickly get into a cascading effect where the stuff gets darn hot, smokes like the dickens, and melts plastic containers. I had that happen once when I dumped a filler material on top of about 4 ounces of epoxy and got distracted and didn't start mixing it in right away. My theory is that the filler material on top insulated the epoxy and didn't let heat escape, and started that cascading effect.
West is very popular, but I like the 2-part epoxies like System Three and RAKA (and they are much less expensive than West to boot.)

[Al Lupone]

WEST & SYSTEM THREE are two different products from two different companies with different mixing ratios & different hardeners. I don't believe you can mix them.

Al

[Bob Johnson2]

Mike, if you get the hardner and resin too cold before you mix it the pumps work real slow. They still work, just really slowly.

[James Biddle]

WEST & SYSTEM THREE are two different products from two different companies with different mixing ratios & different hardeners. I don't believe you can mix them.

Al

QFT

Also, the West system comes with 3 pumps that each have different mixing ratios. They must be installed on the corresponding cans correctly. I made up a batch at 70 degrees a few nights ago and had at least 25-30 minutes to play with.

[Mike Cutler]

Ooooops Sorry for the confusion folks. I have the "System Three" product line. I don't know why I crossed those up. Start typing and disengage brain, and if you type as slow as I do that's a lot of disengagement. I actually had originally wanted to use the West product line, but I couldn't find it in small enough quanities locally. You'd think with the zillion boat yards in New England I wouldn't have had a problem, but they seemed to all have it in large quanities, and none of them had the 209 hardner
I am going to try the Sytem Three "C" hardner, it's supposed to give a 70 minute pot life. I also will wait for the shop to cool off a bit. I went back and read all 51 pages of the epoxy manual, and dowloaded some additional info from them, so I think I'm ready to experiment a bit more. So far I like the end result. I did a goof test piece where I applied epoxy to the edge of board and set another piece on top of it, no clamps, no joining, no prepping the edges of any sort. 18 hours later I whacked the joint with a deadblow mallet and there was no evidence that the adhesive had failed at all, it did not break on the glue line.
If I still don't get the results I need, I'll be back asking more questions, but I'm pretty sure that you guys have me on the right track now.

[Frank Hagan]

One other thing with epoxy ... make sure you have enough of a gap for it to provide the bond. You can squeeze too much out in a very tight joint (I don't have that problem, but some of the woodworkers here might!) And some people report problems making epoxy "stick" to white oak, so check with System Three for their recommendation if you are using epoxy on white oak (RAKA recommends wiping with acetone just prior to epoxy application).

[Bob Smalser]

One potential problem with epoxy in thick stock is your wood.

If you have to pull a slightly-warped board in hard with the clamps, you may squeeze too much glue out of sections of that joint for a lasting bond. Make sure you use a high-adhesive thickener in those applications....it doesn't squeeze out as easily.

Such situations are where I sometimes go to liquid poly, which likes a lot of clamping pressure, but needs tight joinery and a tad of moisture.