Speak to us of epoxy strength

[Brian Kent]

When I am gluing rockers to legs on a fared joint with dowels, the recommended glue is West System epoxy. I need several drops of it. I know it doesn't go bad, but I am trying to avoid a $38 quart of resin and a $30-40 quart of hardener plus $14 in pumps.

Is there a great deal of difference in strength between West System and some $6, 15 minute epoxy. I just don't have an extra $80 plus at the moment for several years supply of epoxy.

Any good suggestions for strong epoxy in smaller volume?

[Faust M. Ruggiero]

Brian,
West System epoxy is kind of thin in the viscosity. You need micro balloons to give it thickness. Off the shelf epoxy from your local hardware store is probably a better consistency for your use. I can't figure out why the author of your direction sheets recommends epoxy at all unless he wants the slow dry time to allow the glue to soak into the wood. I would imagine that is a fit many people would not hit perfectly and maybe he allows for the gap filling ability of thickened epoxy. In any event, I am sure any good brand carried in small volume by a local store will work fine. If you want some of the "real Macoy" PM me and I will raid my wife's cosmetic drawer for a couple small plastic bottles and send some to you. I too have a life time supply. In fact, I keep looking for a project that cries for one of those 1/4" thick epoxy finishes.
fmr

[Curt Harms]

I did a bit of research on this. If you have the time & inclination you can find manufacturers' data sheets including "strength". DevCon epoxy is available at my local Ace, System Three at WoodCraft. The System Three 15 minute seemed a good bit stronger than the DevCon. I suspect either would be more than adequate. I wanted bottles rather than squeeze tubes or syringes. It seems the bottles remain usable thru multiple uses because the tips are easy to keep clean. I did have system three 15 minute get thicker after several years to the point it was hard to mix so i tossed it. But I'd say it stayed good for 5 years or so.

[Joe Kieve]

Brian,
Many years ago we broke a dinner plate and I glued it back together with Elmer's epoxy, two small tubes I bought at the hdw. store for a few bucks. Don't know if it's still available since that was over 30 years ago. That plate is still intact even after daily use and many hundreds of trips through the dishwasher.
I've also used JB Weld and many people swear by it.

Good luck with your glue-up.
joe

[Mike Henderson]

Use the slow epoxy that you can get at the Borg. Works fine and is plenty strong. Even though I have West Systems in the shop, I often use the 1 hour stuff because it's faster. I've also built a number of chairs and used the 1 hour stuff on them and there's no hint of failure. The 1 hour is stronger than the 5 minute.

If you're really worried, pin the dowel from the inside or back of the leg (two pins) where the pins won't be seen easily. On one rocker I made I put two screws into the dowel (from the inside of the leg), and also glued it with epoxy but I think that was way overkill (used plugs over the screws). The front legs are the critical joint.

Mike

[Brad Shipton]

I recently tried out the new West 610 Epoxy, and it is a wonderful product. It comes in standard chaulking tubes and is much thicker than the West 105 system. The bond strength is only slightly less than the 105. You do need their special mixing tube, but these are not expensive. I bought the tubes for $28 each (CAN$).

Brad

[Sam Layton]

Hi Brian,

I have never used West Systems Epoxy, so I can not comment on it. I have used DevCon Epoxy for things around the house, (not woodworking projects). I have purchased other brands, such as Loctite, because the DevCon was not available. A couple brands I used did not cure well. DevCon is the only brand that I have been happy with. So, what ever brand you decide on using, glue up some test samples to see how you like it, and how it cures.

Sam

[Darnell Hagen]

I know it doesn't go bad

Ya, it does, at least my DevCon has a shelf life. When mixed it goes Mountian Dew yellow.

[Henry Ambrose]

West System is thin for a reason - it will wet out and soak into the wood and give the strongest bond possible. West System 105 series is made for wood - many (most) other epoxies are not, they're made to be good for everything, one size fits all. When you use the 105 series materials, brush on a coat of unthickened resin before you add the filler to the remaining mix then put a layer of thick stuff in place and assemble.

They do sell small "Repair Packs". They're a lot less money than buying quarts and they solve the mixing problem for you since they are premeasured doses.

http://www.westsystem.com/ss/105-system-kits

West Systems also has --extensive-- information on how to use their products posted to their website. Read up on the material you're using and learn how to use it to best advantage. If that's not enough they offer great technical help via email and phone.

I buy it in gallons its great stuff!

[Howard Acheson]

>>> Is there a great deal of difference in strength between West System and some $6, 15 minute epoxy.

No. In fact, there are relatively few manufacturers of epoxy. Most of the brand names comes from a small group of chemical companies.

Remember, when using epoxy, you don't want real tight fitting joints. Epoxy gets its strength from a certain amount of film thickness unlike waterbased adhesives.

[Brian Kent]

I just got back from a local hardware store that has 60 minute epoxy rated at 3800 psi bond strength. All I know about that is that System 3 has a lower bond strength and 3800 is higher than all of the other epoxies on the display.

Luckily, they also had Titebond Hide glue, which I need for the chair spindles.


Thank you all.

[Noah Katz]

"West System is thin for a reason - it will wet out and soak into the wood and give the strongest bond possible."

In a pinch you can get the same effect by applying the epoxy and hitting it with a heat gun which makes it runny and absorb into the wood.

"Remember, when using epoxy, you don't want real tight fitting joints. Epoxy gets its strength from a certain amount of film thickness unlike waterbased adhesives."

I haven't heard of that, and it doesn't make sense to me. Got a reference?