Epoxy Application - How Much to Apply?

Using 5 min epoxy to glue larger scale figures, legs and arms. Instructions are a bit vague as to how much will do the job.

Any experience here as to how much/little you can get away with to get the job done?

Also no mention as to whether or not temperature of the epoxy will effect its ability to cure. Any truth to that? Sometimes I forget and leave the tubes in the garage overnight and they are a bit cold when I want to use them the next day.

thx - Craig

Reply to
Musicman59
Loading thread data ...

You only need enough to span any gaps between the parts. Realistically, most epoxies are stronger than the materials they're gluing.

Uncured squeeze out can be removed with a cloth dampened with alcohol.

The cure rate is primarily set by the resin-hardener combination. But, cold epoxy takes longer to cure. In the quantities we typically mix for models, there's not going to be much difference between cold and warm.

If you need more working time, 2 Ton epoxy cures in a nominal 30 minutes instead of 5.

Cheers, Dave

Reply to
Dave Ambrose

Yes...yes...and maybe...

"Enough" can depend on the type of the epoxy - if it's readily sandable, "enough" may mean slopping on enough to be used as a filler. If it's not readily sandable, then you'll want to use the minimum amount to cover the join and use your favorite filler/putty over it. Cured consistency of two-part epoxies can also depend on how exactly you mix them - sometimes if they aren't mixed in proper proportion they can come out gummy or rubber-like.

As to heat speeding curing - yes/maybe, again, depending upon the particular epoxy. Most of the ones I've worked with tend to be exothermic as they cure, and at work we often use a heat gun to speed curing of industrial epoxies...but again, it all depends on which one you're using.

Yes - we also store industrial epoxies in the fridge to enhance shelf life (in fact, I think I have a pack in my kitchen fridge right now that I'd forgotten about...). Test a sample - if it warms as it cures, chances are that putting a bit of heat on it after mixing will speed it's cure time...but be careful not to melt or burn your work in the process.

Reply to
Rufus

thx. I'm using the regular off the shelf 5 minute epoxy from Ace Hardware for use on 1/6 resin figures... Never thought of it as a gap filler. The recast figures I have have lousy joints. it may help me to let the stuff ooze out and not wipe it off...

Craig

Reply to
Musicman59

Yeah - and you could mix in some microballoons to boot -

formatting link
Can order from Tower, or you should be able to find at any R/C shop. Experiment with your mix before you apply to the figure so you're sure you've got what you want.

I've heard baking soda also works, but I've had issues with baking soda going flaky on me over time when I've used it as a "grit" in painted wing walks.

Which now give me a an idea...

Reply to
Rufus

Microballoons are a very good additive if you need a filler. You can also use very fine silica, which will increase viscosity without reducing the epoxy's density.

In either case, you need to use breathing protection when using them in dry form.

Baking soda is water soluble. I wouldn't use it as a filler.

Cheers, Dave Ambrose

Reply to
Dave Ambrose

I have found several epoxies suggest limits of 1/8 inch thickness. The thicker the layer the hotter it gets during cure, and can warp or crack or other bad things.

One time I had mixed too much (this was for an actual epoxy-fiberglas layup. I had let the mixed epoxy sit as I finished putting the glass cloth into the layup and started smoothing and squeegee-ing. I happened to look over and the paper cup the epoxy was in was charing brown and black, and smoke was coming from it. Had to take it outside as I was afraid it would start a fire! You might use a little less hardener/catalyst for thicker applications.

Reply to
Don Stauffer

I have used it as a gap-filling putty, and even used it to cast small parts (plaster mold).

Reply to
Don Stauffer

I use Super T glue and have had no problems with large figures. I have put together resin and vinyl with no problems. You don't have to use epoxy. I would suggest that you put an excellerator on side and super glue on the other. This will give you a good bond

Dan

Reply to
Dan

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.