I have a Bending Branches wooden paddle that got broken along one side of the blade. It is a smooth break and fits snugly back together. What is a good glue to repair this with?
Epoxy de best…
– Last Updated: Aug-27-11 3:09 PM EST –
Second best be Titebond III. Yer gon'na varnish over de blade repair ah' reckon'?.
Not a big fan o' polyurethane glues - i.e. Gorilla glue contrary ta all de hype.
FE
fits back together …
– Last Updated: Aug-27-11 4:05 PM EST –
...... I know you said it's a smooth break , but fits back together makes me think there may be some splintery sections in the break , or something other than smooth and flat .
Just posting this as food for thought because sometimes it's a bit trickier and takes longer to fit a break back together after you have the epoxy or glue placed , than it does to test the refit while it's still dry , just something to think about .
The thing with gluing up a break that has some (any) splintering is you need time enough to get the glue into all the areas that will (in the end) fit back together , and get everything in proper alignment to clamp up .
Epoxy "begins" to stiffen up some right off the bat after catalyzed (though only a little) , and continues stiffening until it takes the initial set . Well before that intial set the epoxy is really too stiff to make any critical adjustments to the fit of things . One little splintery piece in there that is giving you a difficult time getting the perfect alignment has the potential to get you into a rush for time pretty quick .
Epoxy's rather stiff viscosity wise (but can be thinned some) , and doesn't flow like say the Titebond or similar glues do , so it takes a bit more time to get the gluing surfaces coated .
The different rates of set for the epoxy (slow,med, fast) and the temp. of the material are factors that determine how much time you actually have to mix and place the epoxy , get the fit you want , and clamp up (and then there's the clean up of the squeeze out before it gets too stiff) .
Not saying don't use the epoxy , just consider the break complexity (if any) real carefully and the working time you'll need before going with epoxy over say the Titebond . Time is your friend before clamp up , the more the better in many break cases .
Will you reinforce the blade break area afterwards with 4-6 oz. glass cloth ??
I agree - epoxy.
– Last Updated: Aug-27-11 5:20 PM EST –
Although I am a fan of Gorilla Glue for some applications, this is not one of them. I would use a marine epoxy.
Before you mix any glue - along with the considerations mentioned by Pilotwings, you need to test out your method of clamping the glue-up. Clamping a paddle edge-to-edge can be a bit of a trick to keep everything lined up and snug - especially if the blade has any camber to it. You need to make sure everything lines up straight and that all excess glue will be squeezed out (but not so much to create a "dry joint"). I would probably make a two-part jig to hold everything in line while clamped.
If there is any splintering or chinking, I would consider cutting that section out - even if it's just a blade width - and laminating in some replacement wood. Doing so will also require a jig or "carrier" to hold an already shaped blade with shaft perfectly flat for the cut. If you can't match the wood that's there, you could always "bookend" a matching strip on the other side of the blade.
With a clean and straight repair using epoxy, I wouldn't worry about reinforcement. Just do a good repair and make sure you get 100% coverage on your glue line and refinish the blade for a good seal.
Even G-flex is thin enough to work
into a crack by gently working the crack open and closed. It has a long working time.
When a crack narrows severely, I have sometimes put West 105/205 into a syringe and forced it into the crack. If all one has is a dental or glue syringe, one can drill a small hole near the narrow end of the crack. The hole should be a tight fit for the tip of the syringe, and shallow. The tip is pushed into the hole and epoxy is forced into the crack.
In general, one should not use a hardware store grade of epoxy for wood repairs. Quality epoxy (West, System 3, Raka) is kinda expensive, but 4 oz bottles of West G-flex are about $16, and that’s a lot of paddle crack repair.
Gorilla glue would be fine
it is water proof. However, because it expands some what forcefully, you need to have a good clamp plan. And use tape along the sides of the crack to help clean up of the squeeze out. I used it to glue a cracked wooden swing seat, it has held up well for about two years outside. Epoxy will also work well, but you don’t have to mix Gorilla glue.
gun stock glue
Go to brownells.com under keyword type in hot stuff.
It will pop up for Hot Stuff Instant Glue.
Never tried it, but heard lots about it; even in national magazines.
epoxy
I do use gorilla glue (among others) when I make paddles, but I would use epoxy for your repair. As said before, if you have a good clean wood to wood joint, reinforcing should not be necessary. If there are any “small” gaps, epoxy will fill them with more strength than gorilla glue (which fills spaces by foaming up). Of course, you need to clamp this fix regardless of your glue choice.
Clamping
Gorilla Glue and other polyurethane glues require VERY firm clamping, as stated above.
Epoxy should NOT be clamped really tightly, as it can force the glue out of the joint, resulting in a weak, glue starved joint. The best way to use epoxy for this type of repair is to coat the wood with plain epoxy, which it will absorb, then butter the joint with thickened epoxy and clamp it using moderate pressure. You should see some squeeze out all along the joint, which indicates that there’s sufficient glue in it.
It’s just cyanoacrylate (Super Glue)
– Last Updated: Aug-29-11 12:43 PM EST –
Personally, I wouldn't use cyanoacrylate for any wood repair. You may get away with it for bonding a minor crack that fits together perfectly, but it's not likely to work on a paddle blade that's in two pieces.
OK, but I don’t find thickening
necessary, nor, at least with hardwoods, do I find the wood soaking up the epoxy to a marked degree. When I’ve dealt with one-ended cracks like the OP describes, I’ve gotten plenty of West epoxy in for squeeze out on the first pass, with good results.
If I were glueing up an entire panel for a paddle blade, that might be where I would thicken the epoxy a bit, because small gaps need to be filled if the jointing of the pieces is less than perfect.
Yeah, I’ve seen a “super glue” for wood
but isn’t it the case that super glues are just a bit susceptible to water? Super glues often seem more “interested” in setting to themselves than to what one wants to bond together.