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Hello,
I am an artist who is going to start making my own canvas panels to paint on. When nail gunning 4 bars of wood together (to make a square frame) I also need glue to reinforce the joints. Will normal wood glue do or is there a more professional stronger glue out there?
Kind Regards,
Katherine
there is no point making a glue joint that is stronger than the parent material. It's a common error.
Normal PVA woodglue makes a joint about as strong as timber, but it relies on the faces being hard against each other, so you need to make your joints flat and square. If you have substantial gaps in the joint then your problem is filling not glueing. Epoxy with a filler is about as good as anything for that. Araldite, or epoxy mixed with wood dust or filler beads are common options.
Finally PVA into endgrain can get soaked up leaving inadequate glue in the joint. Best to use extra on endgrain.
If you really want to make your corners stronger some triangular blocks into the corners makes the glueing area much larger and the whole thing stiffer and stronger. Clamps to hold them in place, spring clamps are cheap and easy.
Yes the normal white PVA wood glue will suffice your needs. In gluing timber the glue is only as strong as the timber. If/when a glue joint has been broken in most cases it has ripped/pulled out the timber.
And welcome to the site:2tsup:
Welcome!
If it is just frames that are basically flat on flat surface, then go for the cheap PVA. If you are doing more interesting joints that might have a bit of play in then like dowel rods into square frames or angled joints that don't quite meet up, then I suggest durabond which is a polyurethane glue which foams a little and will take up any voids in your joint.
It is waterproof (PVA will break down if it gets wet) and very tough and does not dry brittle so the joint is more likely to survive if the frame gets a sharp jolt. The downside is that it is more expensive, but probably cheaper than epoxy.
Good Luck :)
If you're using mitre joints on the corners, you should reinforce them with splines, otherwise they aren't very strong. I think most picture frames are done with finger joints, which are quite strong, but take longer to do. If you just use butt joints, they will need to be dowelled as they have virtually no strength by themselves.
PVA is fine as long as you take care.
From way back in the dim dark past, the frames need to be beveled also, so that only the outside corner of the wood is touching the canvas. The corners had finger joins, but no glue. They are held together by the pressure of the canvas stretched over them. I think you can put wedges in the corners to make sure the corners stay square. And on longer sides, a brace is put across to stop bowing. If you cant do the finger joint thing, maybe biscuit joints would work, with just pva glue. But I think you need the bevel so that you don't have the whole strip of wood making a stripe down the edge of the canvas.:)
Splines would work in the corners to perhaps. You can do them just with a saw. No buying yet more tools. Although that may be aganst the instincts of most people here.:d
are you sure about this? I understand picture frames aren't likely to be subject to a lot of stress, but in other situations, I would think the stronger the joint the better.Quote:
Originally Posted by damian
The variable to consider is the direction of force. Imagine trying to pull a length of timber in half by grasping each end and pulling it like a Christmas cracker, as opposed to snapping it directly across the grain, or tearing it along the grain into two long strips.
I've used Kleiberit 501 and its an awesome glue, its not a lot more expensive than PVA, but its strong like you wouldn't believe.
I think Tea Lady is on the money. It looks like Katherine is looking to make stretcher frames not picture frames. The joint in the corner is usually a bridal joint which holds together under the pressure of the stapled canvas.
If you were to glue the frames, no nails would be required, however you lose the ability to be able to wedge into the corners to tighten the canvas if it becomes loose.
Regards
woodcutta
Yep I agree with damien. If you use a modern PVA and the joint is properly prepared, ie no gaps, then once it is cured and you try and break the joint it will break on a grain line not the joint line. There's no point in strength once the glue is stronger than the timber. The choice of glue should be made on the basis of desired working time, cure time, durability for conditions, quality of joint, etcQuote:
Originally Posted by SilverSniper
Cheers
Michael
Hey katherine are you totally bamboozled yet?
White glue, PVA you ordinary wood glue will be strong enough provided you have mechanical linking (nail, screw, interlocking wood)
Yellow glue or cross linking wood glue will be stronger (more expensive) but may be of benefit if you are after quicker drying times.
both clean up in water.
epoxy and polyurethane are stronger but harder to clean up
I wonder whether normal PVA along with pocket hole screws would do the job better then some I've seen which appear to be stapled together
Here is the basic variety sold by carba-tec
As Mic-d says, if the joint is stronger than the parent material it'll just break through the parent material. Many glue joints are a little stronger than the parent material so it's pointless fretting over stronger glues. PVA is one of these on timber.
The real issue is preparation of the faces to be glued. As above you can get into all sorts of jointing options depending on your requirements and tooling and budget etc. I have no interest in painting so don't know anything about the frames, I had assumed the questioner has investigated this elsewhere. It seems others here know something about the requirements and have offered sensible suggestions.
As I said, for glueing good fitting faces PVA will be adequate, cheap and convenient. For filling epoxy plus a filler medium is a common and effective choice.
If the timber fails, who cares how strong the glue was - its still holding.Quote:
Originally Posted by SilverSniper
Caulobacter crescentus bacterium produces the world's strongest glue.
The adhesive can withstand an enormous amount of stress, equal to the force felt by a 10c piece with more than three cars piled on top of it. That’s two to three times more force than the best retail glues can handle.
Unfortunately, scientists haven't been able to duplicate it....yet.