Using epoxy on dowels?

[Brian Penning]

Looking for thoughts on using epoxy with the compressed fluted dowels.
I do a lot of chair repairs and often the replacement dowels fit loosely in the cleaned out holes.
Due to the looseness(gaps) I'd like to use epoxy. Was wondering if the epoxy would also expand the dowels similar to the way water based glues act on the newer compressed dowels.
Any thoughts?
TIA

[Mack Cameron]

Looking for thoughts on using epoxy with the compressed fluted dowels.
I do a lot of chair repairs and often the replacement dowels fit loosely in the cleaned out holes.
Due to the looseness(gaps) I'd like to use epoxy. Was wondering if the epoxy would also expand the dowels similar to the way water based glues act on the newer compressed dowels.
Any thoughts?
TIAHi Bri; my initial thought would be NO!

[Cliff Rohrabacher]

If you want to expand the dowels, wet them before installation then when they are all dried out epoxy 'em & you'll have a repairable joint.

[Ron Dunn]

There seem to be a couple of things wrong with this idea.

1. Epoxy is frowned upon for repairs to furniture. It isn't easily to undo in future.

2. The epoxy won't expand the dowel.

and Cliff, won't the dowel pull away from the epoxy as it dries out?

[Brent Smith]

Hi Bri,
I tend to agree that epoxy isn't the way to go. Depending on the value of the chair, either plug the hole and redrill and use hide glue, or use shims and Titebond to do the repair on everyday pieces.

[Mike SoRelle]

Hi Bri,
I tend to agree that epoxy isn't the way to go. Depending on the value of the chair, either plug the hole and redrill and use hide glue, or use shims and Titebond to do the repair on everyday pieces.


I've made the terrible mistake of using epoxy and once I used gorilla glue on chairs, it's hell to fix, and you will be fixing it at some point.

Now I use hot hide glue, it's just about the only place I use it, but it works well and it's easy to repair when (not if) needed.

It's more trouble than it's worth to me for general use, but on anything I think will need to be repaired later, it's the first glue I go for.

Mike

[J. Z. Guest]

Epoxy won't expand the dowels, but you don't need to expand them. Epoxy turns into plastic when it cures, and is the best gap-filling adhesive we have to work with.

Epoxy IS the way to go in this case, and in any case where a joint doesn't fit as tightly as it should. (unless you want to redo the whole joint) Lots of folks don't feel comfortable with it because it isn't a classical woodworking adhesive. Those same folks didn't give poly glue a chance when it came out either, and the same type of folks probably didn't like white glue when it came out as an alternative to hide glue. Time marches on. Epoxy rocks.

[Mike Cutler]

Brian

Epoxy, with a gap filler will do well in this application. However you may want to invest in a dowel plate and begin to make your own dowels. Redrill the holes, if possible, and go to a larger dowel.
I doubt that the dowels will swell with epoxy as much as with water.
I'm a little biased toward epoxy. It's the most preferred, almost exclusive, adhesive I use.

Here is a thread on "Repairable Glue Joints "by Bob Smalser.

http://www.sawmillcreek.org/showthread.php?t=21822

[Brian Penning]

That was indeed a great old thread. Further gave me more assurance about using epoxy, especially for repairs.
FWIW I've been using epoxy for several months now and so far no one has come back complaining. Granted, it's months not years I've been using it.

I'm experimenting a bit with soaking the dowels in water and then drying them out as per Cliff's suggestion.
So far, upon soaking them for 30 minutes or so they increased in diameter by 10 thou when I measured them wet.
Will remeasure when they dry out and see if they still hold that increased diameter.



Brian

Epoxy, with a gap filler will do well in this application. However you may want to invest in a dowel plate and begin to make your own dowels. Redrill the holes, if possible, and go to a larger dowel.
I doubt that the dowels will swell with epoxy as much as with water.
I'm a little biased toward epoxy. It's the most preferred, almost exclusive, adhesive I use.

Here is a thread on "Repairable Glue Joints "by Bob Smalser.

http://www.sawmillcreek.org/showthread.php?t=21822

[Chris Padilla]

Has anyone actually SEEN a "compressed wood" dowel or domino actuall swell? Do we know for a fact that they do swell? If so, how much? Is it really significant? Is it really a big deal in joinery?

The dowel could be made larger wrapping some thin veneer around it.

One reason I like epoxy is open time. You can get epoxies with open time all over the map from 30 seconds to 3600 seconds! On top of that, it is the strongest adhesive out there, fills gaps admirably, and is pretty much heat and water proof. If you want it stainable, mix in some sawdust with it. If you want it to flow like water, warm it up a hair and it will soak into the wood better.

[Chris Padilla]

I'm experimenting a bit with soaking the dowels in water and then drying them out as per Cliff's suggestion.
So far, upon soaking them for 30 minutes or so they increased in diameter by 10 thou when I measured them wet.
Will remeasure when they dry out and see if they still hold that increased diameter.

LOL! I kinda missed this when I put in my little "rant" above.... :o

However, I'd say that glue isn't pure water and wouldn't cause the same swelling of pure water. Presoaking...well, let's hear your results. :)

[glenn bradley]

I would make my own dowel to fit or if there were too many, plug, redrill and use standard dowels. No to expoxy is my vote. Filling a bad void with goo is not a good solution; it will fail again. Drilling, plugging and redrilling is better for me.

[J. Z. Guest]

Filling a bad void with goo is not a good solution; it will fail again.

But it isn't filling it with goo. It is filling it with goo which turns to plastic via a chemical reaction in 12-24 hours. Epoxy doesn't shrink like yellow glue, nor does it foam like poly glue.

[Eric Gustafson]

Has anyone actually SEEN a "compressed wood" dowel or domino actuall swell?

That is such a good question, Chris. I took some biscuits and soaked them in water. I measured .001" on a #20 biscuit. Insignificant on a biscuit, anyway. Now, I need to try the same trick on a domino. My BIL did assemble some thing with the Domino and put just put a drop of water on the joint, without glue, and you cannot get it apart.

[Jacob Reverb]

I'm with Jeremy. In the right application, there is nothing that has more tensile strength than epoxy, including high-carbon steel.

I use epoxy quite a bit in marine applications, and it's good stuff.

If you use it correctly and get a good bond, you won't be fixing it again...I guarantee that. Because it's not going to come apart, ever.

Epoxy has its caveats -- you need a much thicker layer than with, say, Titebond; and it can't be disassembled without quite a bit of heat; and it's messy and the amines can be toxic -- but in some situations, there's nothing better.

[Mike SoRelle]

Everyone seems to be focusing on the joint and the strength of <insert_favorite_adhesive_here> but is losing sight of the fact that we're talking about chairs, made out of wood, the joints really aren't the problem in most of the chair repairs I've had to do, it had more to do with the abuse it suffered due to oh, say, my teenage daughter's friends leaning back in them and doing wheelies, or stepping and standing on non-structural pieces, etc etc, repairing that epoxied joint when the wood breaks off next to it is a royal PITA, and that's true of most of the glues except ones like hide that are relatively easy to break the bond and remove, PVA is just about as much of a pain as any.

In terms of the OP's issue, it seems to me that packing a joint full of adhesive isn't really a fix but more of a bandaid to avoid the real fix of plugging and redrilling and/or milling and using a larger dowel.

I'm 33, so the whole time marches on comment certainly doesn't apply since most all of the adhesives discussed have been around for my entire life, and I certainly don't eschew the 'new ways' but I damn sure don't discount the 'old ways' when the old way works and has one hell of a long track record to prove it.

My $.02

Mike

[Cliff Rohrabacher]

1. Epoxy is frowned upon for repairs to furniture. It isn't easily to undo in future.

Wouldn't that depend on whether you ever wanted to take it apart. And if it breaks epoxy is repairable on an order far superior to a lot of the other modern glues.


and Cliff, won't the dowel pull away from the epoxy as it dries out?

I should think not. I've done it with ax and hammer handles all my life.

[Michael Schwartz]

Epoxy is nice in gap filling situations or situations where the joint is not tight fitting. If you have a tight fitting dowel or joint you might as well just use yellow glue.

Although if your assembly is large and complex a slow setting epoxy such as epotech 100 will give you several hours of open time.

You can also take it a step further and use epoxy and threaded rod. Not only is threaded rod stronger but with it you can avoide some of the long term problems of dowel joint failure due to wood movement.

[Chris Padilla]

That is such a good question, Chris. I took some biscuits and soaked them in water. I measured .001" on a #20 biscuit. Insignificant on a biscuit, anyway. Now, I need to try the same trick on a domino. My BIL did assemble some thing with the Domino and put just put a drop of water on the joint, without glue, and you cannot get it apart.

Well I'm just going to have to try this since I have a box full of dominos at home. I could also try it on a biscuit to see if I get the same results as you did, Eric. I have dowels but I dunno if they are compressed...I don't think so but I could try that as well. What the heck...an easy experiment!

[Chris Padilla]

I'm 33, so the whole time marches on comment certainly doesn't apply since most all of the adhesives discussed have been around for my entire life, and I certainly don't eschew the 'new ways' but I damn sure don't discount the 'old ways' when the old way works and has one hell of a long track record to prove it.

My $.02

Mike

I guess we'll see where things are when you're 83, Mike. ;)

[Howard Acheson]

I'm with Jeremy on this. In the shop I was involved with we did a number of repairs to furniture. Chairs are the most stressed furniture item and, if they fail, they are the most likely to cause an injury. That being the case, you want to use the best adhesive that minimizes a failure. It makes no sense to use an adhesive you expect to fail unless you are using an adhesive to retain authenticity for an antique. Then, don't sit in the chair.

Epoxy has a couple of attributes that make it the best repair adhesive. First, you do not have to get the joint scrupulously clean--epoxy will adhere just fine to other adhesives. Second, epoxy will fill gaps so you do not need a perfectly fitted joint. In fact, with epoxy you need to have some space for it to work correctly. Third, epoxy should never fail again. Fourth, epoxy can be opened up later by the application of heat. Finally, epoxy has a slight amount of flexibility to it so stressed joints can slightly "work" without the epoxy failing.

Not only did we use epoxy for all our chair repairs, all our new chairs were put together with epoxy. We never had a joint failure.

[Mike Henderson]

I use epoxy to repair chairs. But why use an undersized dowel? You can purchase dowel stock that's pretty accurate. Drill a hole in scrap and check the fit.

When you're repairing a previously doweled chair, often the old dowel had gotten loose, but maybe not loose enough for the joint to come apart. I take a flush cut saw and saw the dowels, then drill out the old dowel with an undersized bit, and clean out the remainder with a small chisel.

Assembly is the opposite - cut your dowels to length, give them a thin coat of epoxy and put epoxy in the hole. I use a toothpick to put the epoxy in the hole.

Chairs don't fall apart because of the corner blocks. I've seen chairs where the joint has completely failed (meaning when you go to disassemble it, the joint comes apart with hand pressure, once you remove the corner blocks) and people had been using them. 'Course it was somewhat like a rocking chair.

Mike

[Mike Cutler]

Hmm..............

There seems to be a misconception that any epoxy is "gap filling". This is a misnomer, and is absolutely not a 100% true statement.
Certain epoxies are gap filling, other epoxy have to have microballons, aluminum oxide, woodflour, or some other medium to act as the thixotropic(sp.) agent. Some epoxies could be used solely by themself, but I doubt they can purchased in a wood working store, or that you would want to use them. (I've used some that can tear the threads out of a 3/4" NPT stainless steel pipe fittings when the union is broken.)
While they do have better "gap filling characteristics than PVA glues. They can't be just expected to fill any size gap indiscriminately
Other types of epoxy could be used to fill the hole, then milled, drilled and the appropiate dowel inserted. These epoxies come in dozens of colors,and can be mixed for color gradients between two colors, and touched up with oil based paints. Mohawk Finishes has an entire catalog of them.

Like every other adhesive out there, epoxy has to be selected based on application. It's not a silver bullet by itself.
There are probably at least a hundred formulations of epoxy out there,maybe even more. Which may be a contributing reason that folks shy away from using epoxy. That and the mixing, and the upfront increase in cost of the products.

Pick the right epoxy, apply it correctly, and everything goes well. Pick the wrong one, and the experience can turn negative in no time.

I personally like epoxies, and the broad application and use spectrum they cover. But they do have a learning curve.

Just some random thoughts on the subject, and not directed at any one post.

[Peter Quinn]

I'm pretty sure my biscuits swell more than .001". I've done a dry fit, numbered the biscuits to match the slots (had a marginal container of PC biscuits where some were loose, some too snug), put glue on what was a previously easy joint to assemble, and WHAMO, when I try to push in the adjoining board I'm needing a bigger dead blow to whale things together! Something was swelling aside from my temper. I didn't mic them as I don't like glue on my calipers.

I've also seen biscuits swell enough to telegraph to the surface of plywood when the slots were cut off center, closer to the surface a few 1/16's. That's when I use epoxy on em, cause it contains no water and doesn't make them swell! IE: non hydrolic.

This is completely unscientific, but I don't always need science to interpret for me what I have experienced.

[Jacob Reverb]

For anyone ever considering using epoxy for a particular application, let me just add that there are excellent resources at:
westsystem.com
and
epoxyworks.com

West System does extensive engineering R&D on their products and applications of them, using some fairly sophisticated ASTM testing protocols, and they have always been hugely helpful when I've called them with a question about using their products to solve this or that problem.

I have no financial connection to them (unfortunately) :mad: I've just been extremely impressed with their products and support.

FWIW...

[Chris Padilla]

Peter,

I've seen biscuits telegraph through as well but if you let the MC of the wood surrounding the glue restabilize, that telegraphing usually disappears. I guess, technically, anytime we add glue (yellow, white, PVA...any glue that has water in it), it is bound to temporarily swell wood fibers. When it dries, things should shrink back.

[Chris Padilla]

For anyone ever considering using epoxy for a particular application, let me just add that there are excellent resources at:
westsystem.com
and
epoxyworks.com

West System does extensive engineering R&D on their products and applications of them, using some fairly sophisticated ASTM testing protocols, and they have always been hugely helpful when I've called them with a question about using their products to solve this or that problem.

I have no financial connection to them (unfortunately) :mad: I've just been extremely impressed with their products and support.

FWIW...

I like to use Raka, myself. Fair prices and good support as well. :)

[Mike SoRelle]

I guess we'll see where things are when you're 83, Mike. ;)


Lol, with any luck I'll still be around to complain about it, then we can talk about back in the stone age of domino's etc.

Mike