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Posted

Hi

I have just got a 2.5mtr x 200mm x 50mm piece of swamp ash which is getting cut and planed into four 22" x 8"x 1.3/4" sections.

What is the best way to join two pieces to make a body blank ?

Just glue and clamp ? or Use biscuit joints glue and clamp ?

Whats the best glue to use and how long should I leave it clamped ?

Is there anyting else that I should look out for ?

Alan

Posted

This was address fairly recently i think (you might be able to find the topic, although i dont know whether it had an obvious title or not).

If memory serves....the pieces to be glued must be perfectly flat with respect to eachother (no gaps at all). Biscuits arent needed but the clamps must be very tight to ensure a good joint and no glue lines. The glue should be evenly spread all over (but not laid on 1" thick!)

Ppl in the States appear to like Titebond (apparently Titebond I and not type II is used). Where in the world are you? I'm not sure about a UK equivelant as Titebond isnt as widely sold.

I havent actually done this myself yet, so someone else should confirm, reject or add to what ive said

Posted

As far as a Titebond substitute goes I think that any high quality, professional grade wood glue would be fine.

I read somewhere that you do not want a perfectly smooth surface for the join. Can anyone confirm or deny this? The theory is that after you run it through the planer you want to lightly rough it up with 80 grit (IIRC). This raises some of the fibers so they mesh together helping hide the glue line.

This sounds good in theory but does it hold water in practice? I haven't had a chance to try it and have the glue lines to prove it. :D

Posted

Here's some info on the Titebond products from a while ago Titebond I vs II. According to the manufacturer, Titebond II is just as susceptable to joint creeping as Titebond I. I have started using the Titebond Extend (as suggested in that thread) mostly because I like to have a bit more time to set things up.

As for joining the pieces, if you have a jointer - use it. If not, you can use a block plane. You could also place sandpaper on a known flat surface (glass,...) with double stick tape and drag the pieces across it. The point is that the edges need to be perfectly flat AND they need to be perpendicular to the face. If the jointed edges are not perpendicular bad things will happen.

I have always thought that a roughed edge was preferred in this case due to the nature of the glue needing something to grab onto. When joining different woods, the roughed edges help create a little fuzzy edge which makes it harder to see the line. I don't know for sure but I think glues such as Gorilla Glue don't require a roughed surface but glues such as Titebond benefit from it.

Posted

How long to leave it clamped before opening it? Days, not hours. 3-4 days is good. If you are paranoid like me, a week. No need for more.

Guitar Ed

Advice worth what you paid for it. Nothing.

Posted

Yes you need to use a jointer to prepare the edges for gluing. You need to make sure you don't see any visible gaps when you place them together. If you do, go back to the jointer again and get it right. I have used titebond I and II and both work great. Lately, I've been using Gorilla Glue which seems to work alot better. Like they said, after you get done using the jointer, it will leave a super slick surface so ruff it up by going over it with some heavier sandpaper so you can get a better bond. I also like to use Bessey Clamps because they just work really good and are easier to use. There is also a big debate over how tight you should clamp them together. Some say don't clamp with too much pressure or you'll lose all your glue in the joint. Others say it doesn't matter. Either way you don't want it to shift or get out of align so be careful and don't clamp it where it's too loose also. Good luck,, and oh yeah, where did you get your Swamp Ash from? I live in Swamp Ash country.. lol

Posted

I forgot you asked about clamping time. Here's some info from Franklin on this:

What is the clamping and drying time of Titebond Wood Glues?

For most of our wood glues, we recommend clamping an unstressed joint for thirty minutes to an hour. Stressed joints need to be clamped for 24 hours. We recommend not stressing the new joint for at least 24 hours. For Titebond Polyurethane Glue, we recommend clamping for at least forty-five minutes. The glue is completely cured within 6 hours.

I usually leave it clamped until I need to start working on it. I never work on it until it's been sitting clamped for at least a few hours. If I can swing it, I like to leave it clamped for a day. I have never had a problem yet with doing this with Titebond I, II, and extend. I also have read the warnings about clamping too tight and starving the joint but I have not had a problem with this yet either. I apply glue to both surfaces and rub it in with my fingers. I usually clamp it fairly tight and wait for the glue to squeeze out. After about 15 minutes, I tighten the clamps a bit more just in case the squeezing out has left a gap.

This may not be the textbook method but I have not had one problem so far. One thing to keep in mind when clamping is that the clamps (depending on the type) can tend to bend the pieces away from being flat. Dowels/biscuits will help shifting but won't do much to prevent the pieces from being angled/bowed by the clamps. There's a bunch of things you can do to minimize this such as alternating clamp positions, applying heavy weight, using another set of boards/clamps, .... It doesn't matter how you do it but just watch out for it when you clamp. If you see it happening, you'll need to take care of it right away.

Good luck.

Posted

daveq is right... It is crucial to make sure the 2 pieces stay together straight and doesn't move on you before it dries. I personally do the same thing as dave suggested, spread the glue thick(since it can be sanded off easily) tighten it up pretty good while making sure everything is still flush as in the ends and also so that if I was to place a straightedge across the two, It would lay flat all the way across. Then come back a couple of hours later and retighten everything. It seems to make for a better joint. I still think Gorilla Glue would be hard to beat, but Titebond does a great job also. I don't really see a need for bisquit joints myself, since it's not like your going to be standing on it or anything.. lol Also, most people just glue the body together, so that's how I learned by reading and watching what other guitar companies did. But that doesn't mean it's not a bad idea, just an extra step that's just not needed in my opinion.

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