Heat curing epoxy...

[Longcruise]

Ea40  quite a bit thicker than wests

[Kirkll]

Longcruise is right.... west systems does have a pump, but the viscosity is much thinner . The EA 40 is much closer to caulking....

Max..... Are you saying to stab the butt end of the caulking tube into the can?       Man you gotta take a video of that procedure. I got a feeling it's going to be entertaining.

I was thinking more along the lines of a narrow spatula.

or these perhaps

[Buggs]

Honey,
and before someone says the pump is a different color: They are all the same! My point about the West Systems was in reference to the post about getting air in the container, not the viscosity. Don't think West Systems would be using pumps if there were problems with the system.
Honestly, I think you guys are nuts. Nothing seals better than a clean metal paint can lid and lip, which is what those cute little EA-40 cans are. Hell, I don't even use EA-40!
Must have been a different thread where someone was talking about epoxy pumps

[Kirkll]

Well Buggs.... If you DID use EA 40 in a dusty shop environment you would understand why this seems like a good idea to us crazy folks.

Btw....We are all crazy in here building bows from wood and composite materials and expecting them to last 50-60 years being bent and stressed thousands of times... But i can live with it.     Kirk

[Mad Max]

Longcruise is right.... west systems does have a pump, but the viscosity is much thinner . The EA 40 is much closer to caulking....

Max..... Are you saying to stab the butt end of the caulking tube into the can?       Man you gotta take a video of that procedure. I got a feeling it's going to be entertaining.

You would have to cut a 1/4" off the tip to let the air out, STAB slowly

[Buggs]

Back in the 90's, I think it was Red Devil that made a caulking you could color match yourself.
It was quite entertaining to try. Anybody thats planning on putting EA-40 into a caulking tube, should definitely video the process.
Curious on how you will get the air out of the tube, that will be introduced when filling by hand?
Don't think it will rise up to the top like fluid in a syringe. EA-40 is thixotropic, which means it will not flow, even if heated

[Shredd]

  Vacuum and centrifuge...

[Mad Max]

I think I’m just going to weigh it and spray this in the cans

[Kirkll]

I’m not familiar with the term thixotropic. Had to look that one up. An interesting read too, but highly doubt I’ll add it to my vocabulary.

But…heat does change the viscosity on this stuff. When I’m mixing EA 40 I put the cup in the microwave for 15 seconds and the part A turns to a fluid you could easily pour.

The part B hardener doesn’t liquify like the resin does, but it mixes very smoothly after being heated….

With that being said…. I don’t think it would be a good idea to heat this product up very much to transfer it into a caulking tube, then let it set for long periods before mixing. Then again…. It may have no effect on it. I’d have to do a test, or contact the manufacturer regarding heating and reheating the hardener. I don’t think it would effect the resin at all, but one never knows.

I’m thinking heating the cans to 90 degrees over night should make that resin more like thick honey, and the hardener will loosen up a bit more too without effecting the two parts. Actually you could put them in your hot box for awhile to warm them up….

It’s entirely possible this may just turn into a comedy act that we’ll laugh about later….. no balls, no glory!        Kirk

[Kirkll]

  Vacuum and centrifuge...

Hey….. I think you got something there Shredd…. But I want to see the video watching those calking tubes collapse like a thin straw sucking a thick milkshake.

This could be very entertaining …..

[Buggs]

Bloxygen!  Thats the best idea yet. The stuff really works. I know that its used to preserve expensive wine, in addition to protecting anything else you don't want to oxidize. Still need to have an air tight container.

[mmattockx]

EA-40 is thixotropic, which means it will not flow, even if heated

Thixotropic has nothing to do with thinning with heat, it has to do with viscosity changing due to agitation or shear stress.

https://en.wikipedia.org/wiki/Thixotropy


Mark

[Buggs]

Thats interesting about the microwave. I have never owned one(honest), but since there is no thermo-convection with a microwave, the heat is just a by product of exciting the molecules of the material. That would account for the reduction of shear force, which Mark was just reading about.

[Kirkll]

I had an old second hand microwave i put out in my shop to heat my coffee up now and then, but use it almost daily for heating my smooth on..... You should see this thing. Its got epoxy all over the front of it after 10-12 years of use.

Here ya go.... talk about butt ugly...

https://photos.app.goo.gl/fXqNBTGwxhhy3xLy6

[Buggs]

Thats hilarious!   Looks like you got your money's worth out of that one.

I remember the first one I ever saw in action. It was a big as 1970's TV and the food came out looking the same as it went it, but it was steaming. Never wanted one after that.

[Kirkll]

EA-40 is thixotropic, which means it will not flow, even if heated

Thixotropic has nothing to do with thinning with heat, it has to do with viscosity changing due to agitation or shear stress.

https://en.wikipedia.org/wiki/Thixotropy


Mark

OK Mark..... If a microwave is just stimulating the molecules and thinning it down, why couldn't we use this to thin it down and just pour it into the caulking tubes ?    Kirk

[Mad Max]

So I weighted  up some epoxy, I used some restaurant cups like for extra  jalapeno peppers or extra salad dressing and filled them level to the top.
Part A = 71 grams
Part B = 59 grams
I think 71 grams A and 29.5 grams of B will do 1 Recurve with Veneers and lams.

[Shredd]

Wow...  A 12 gram difference??  I been mixing 1 to 1 when I thought I was mixing a plus of 10grams of 'A'...  I am gonna start adding another 10 grams of 'A' to stay on the safe side...

  Thanks for sharing... Important stuff...

   Good Job Mark...     Info of the week right there, if not the month...  To me anyways... 

[mmattockx]

OK Mark..... If a microwave is just stimulating the molecules and thinning it down, why couldn't we use this to thin it down and just pour it into the caulking tubes ?   

I don't see why not. Warn is warm for the most part with epoxies, I have used a double boiler to heat epoxy that had sat too long and developed crystals in the liquid. Heating and letting it cool slowly redissolves the crystals back into solution.

So I weighted  up some epoxy, I used some restaurant cups like for extra  jalapeno peppers or extra salad dressing and filled them level to the top.
Part A = 71 grams
Part B = 59 grams
I think 71 grams A and 29.5 grams of B will do 1 Recurve with Veneers and lams.

Since we're on the subject of mixing ratios and the like, what do you guys find for pot life and room temp cure time when you reduce part B to 1/2 of A?


Mark

[Robertfishes]

I rarely built more than 1 bow a week so I usually bought the quart kits of Smooth On. To get the 2 parts out of the cans I buy plastic picnic spoons, the thicker clear plastic ones are the best ones. Use two different spoons, one for each part... next to the spoons at my Grocery Store are several sizes of small clear plastic cups, I like the 3 or 4 oz ones, they work pretty well.. Weighing each part would be best, I eye ball the parts trying for a 1.25 to 1 ratio. I would mix the parts on plastic dinner plates using a 4 inch bondo squeegee cut in half.. I used the other half to apply the mixed epoxy onto the parts.  I trash the plastics after glue up along with the butchers wrap I had on top of glue up bench. It does not get too cold here so I never had to warm up the EA-40 before mixing. I store the plastics, butcher paper, vinyl gloves in plastic storage totes to keep dust off them. The pint cans of EA-40 each go in a gallon zip lock, dust loves to get on the tops of the cans so the bags and plastic totes help control dust contamination..