How Much Epoxy?

[mmattockx]

For a basic bow that has 3 lams (1 core, 1 belly, 1 back) how much epoxy is needed to glue it up? I understand no one can give me an exact number, but I am looking to make sure I mix enough without having a huge amount left over. The stuff is expensive and I am averse to wasting $$$ if I can avoid it.


Thanks,
Mark

[Longcruise]

More bow materials and bows have been wasted by not enough glue than just about any other cause 🙄  when you look at the cost of material for a bow glue is not that big a deal especially with only three lams. 

Even laying up bows with 7 lams the cost per bow is less than $10. 

HOWEVER,  I do use a system that assures that running out of glue isn't a big deal.   I mix my glue on a glossy finish paper plate.  Each component has it's own plastic spoon.  The  two components are handled without any cross contamination.  Use just a little bit more resin than hardener.  It's easy to judge by eyeball.  Mix it thoroughly using your spreader device.  A piece of lam cut off makes a good spreader.  Keep your cans open and nearby.   If you see you won't have enough,  add more to the first batch and mix.  If you finish with no glue leftover,  Hooray!  If you toss some glue 🤷 no big deal.

Notice that everything used to mix and spread is disposable.

Just go ahead and do it!

[Bowjunkie]

Longcruise's method sounds good.

I used to use little 2 oz plastic 'dixie cups'. It just made it easier to judge how much was enough for any particular bow. I'd then take parts a and b out of them and put it in a tuna fish can to mix and use it from. Now I just go straight from the epoxy container straight to the tuna can. I'd rather have a little left over than run out and have to mix more, but if if that's the case, it only takes a minute or two. Mixing the right amount of glue is one of those things that you get a feel for soon enough.

Disposable? I've reused the same two pieces of osage for dispensing the glue for 20 years. And I'm on my second fiberglass squeegee. I split one once somehow.

[Mad Max]

x3
You have plenty of time to do all this, don't get in a hurry

[Flem]

I'm OCD about wasting epoxy. I use a gram scale so I only use one container, even with the goopy a$$ EA-40. For a blank 72"X1.5"X 2 core lams and glass, front and back; 100gm. I'm not using a spreader/spatula. I use a stiff, cut down, 1" chip brush so its easier to control the spread and avoid slop dripping down the sides.

[mmattockx]

I'm OCD about wasting epoxy.

Awesome, a fellow traveller. Thanks for the numbers, that gives me a starting point.


Mark

[Bowjunkie]

Oh I control the spread baby  We all find our own ways I guess, and it's all good if it works. I don't drip glue over the sides with the fiberglass spatula, that bothers me too. The fiberglass piece sure does clean up easy. Another thing I like about using it is with it I can easily gauge and adjust how much epoxy I'm putting on by feel. It should just barely glide/float on epoxy. If I push any harder, I feel my fiberglass spatula drag on the gluing surface... so I back off a bit. This way I know I'm not putting on an excess of glue, but also know there's an uninterrupted film of glue there, so no starvation gonna happen.

Waste ea40? Pfff, I use that stuff for everything. That reminds me, I'm getting a little low. 

[Mad Max]

[Longcruise]

Max, you appear to be spreading with some sort of modified hatchet?? 😀

[Mad Max]

https://www.amazon.com/Toughest-Tools-Paint-Scraper-Remover/dp/B07XVBW45J

[Flem]

Nice one Max! I like the toothed 5/1

Lots of methods for the same results. Spreading epoxy requires the technique that suits your work style, to be fast and efficient. My main reason for using a brush is to overcome surface tension on any and all surfaces. I don't use high clamping force or coarse sanded glue surfaces, so I need to make sure all surfaces are wetted out.

[Mad Max]

Nice one Max! I like the toothed 5/1

Lots of methods for the same results. Spreading epoxy requires the technique that suits your work style, to be fast and efficient. My main reason for using a brush is to overcome surface tension on any and all surfaces. I don't use high clamping force or coarse sanded glue surfaces, so I need to make sure all surfaces are wetted out.

I just took a file to it

[mmattockx]

Lots of methods for the same results. Spreading epoxy requires the technique that suits your work style, to be fast and efficient.

This is my problem, I don't have a method sorted out yet and I'm trying to get some guidance to keep things from going too far off the tracks.


Mark

[williwaw]

I'm then looking around the shop to see what else need gluing back together.

I let various stuff that needs repair collect so I can justify mixing more than needed. After the mission critical job is done, I can use the rest on other things. I upend the mixing cup into a plastic "paper plate".
it keeps the pot life up by not letting it build heat. A little saran wrap and I can chill it in the deep freeze if I want to do the other repairs after a while.

keep the epoxy cool and the work warm...

[Tim Finley]

I use the 8oz. solo cups,  part B (the brown colored) I mix just less than half of a cup, part A I mix just a little over half a cup this fills one cup and will be enough for a 3 lam bow . I spread with a plastic bondo type spreader you get at automotive stores that autobody people use. I cut them in half and I have 1 3/4 " wide paddles which is the width of my lams .

[Flem]

Solo cups Love em!

Here's a trick for spreading thixotropic epoxy like EA-40. But only if they have a long gel time!
Also enhances penetration in wood and cuts down glue up time. The heat setting depends on how much of a thrill seeker you are

[bigbob2]

For a four lam HH style longbow plus  two pieces of glass, I used 72 grams part A to 58 grams of part B with smooth on.

[ONE SHOT]

For applying epoxy on all my lams I use a wall paper rubber roller. You can get it at Home depot etc. It cleans up really easy with soap and water in a bucket. And will last for years, cost is around $10.00. I dont worry about making up to much epoxy because I use the left over glue for riser blocks that I have made in advance. I cut my own trees and cut them  into  48 inches long pieces then I split them and saw my slats both for more Bows and risers..

[Jeff Freeman]

I use one solo cup on an ounce scale. Two separate stir sticks to scoop out what I need from each part, a and b then I mix no problems. JF

[Mad Max]

For applying epoxy on all my lams I use a wall paper rubber roller. You can get it at Home depot etc. It cleans up really easy with soap and water in a bucket. And will last for years, cost is around $10.00. I dont worry about making up to much epoxy because I use the left over glue for riser blocks that I have made in advance. I cut my own trees and cut them  into  48 inches long pieces then I split them and saw my slats both for more Bows and risers..

Show us how you cut them into slats from split logs