Glue

[vintage frames]

I'd be interested to know which wood glues are preferred by framers. Like Graysalchemy, in another posting, I've recently been using a moisture curing glue, Gorilla, for its' advertised strength. The downside was the mess it made on your fingers.
However, a few of my frames arrived at their customers with open mitres and even though they were damaged in transit, I was hoping the glue would have held better.
On looking on-line I noticed this,
https://woodgears.ca/joint_strength/glue.html
and have started using the Titebond 111. It is certainly a much less agressive and cleaner glue to use, and so far appears much stronger.
Has anyone a better suggestion?

[Jamesnkr]

I'm not sure he's in a position to come to any conclusions with such small sample sizes. I'd want to see 20 or more tests of each type of glue. The problem is that joint strength will follow a normal distribution - a top hat curve. Given the inconsistent nature of wood, I'd imagine that the curve will be quite wide, making it impossible to draw conclusions with so few samples. With only two or three samples, it's quite possible to end up with very skewed results.

His testing machinery isn't that great either, he needs an Instron, but I'm impressed with his improvisational skills.

[prospero]

With obeche and similar open-pored woods I'd say the good old PVA is as good as anything. When you get to oak and ash you can get very dense bits. Oak in particular. Sometimes the cut surface is like glass and there is very little the glue can get a key into. In certain cases I have used slow-setting epoxy for oak and even drilled tiny holes in the faces for the glue to ooze into and form a sort-off joint. You do have to clamp it well as the curing process can cause the joint to open - depending on how much glue you have put on. Same with polyurethanes which can ooze out and near impossible to remove without spoiling the frame finish.

IMHO it doesn't matter how titanic the glue claims to be. You can only expect so much from it. If your joints are cut accurately so that the mating faces fit tight over their entire area and you pin it in the right places then that's 99% of the strength.

[vintage frames]

I think you're right. I do rely on the glue being as strong as possible but was only pinning the mitres closed previous. I'll have to go on to clamping each frame, which is a pain on multiple projects, but will allow the glue to form a stronger bond.
I'm still happier with the Titebond 111, in as much as there's less mess.

[Graysalchemy]

I have taken to clamping large troublesome frames using a ratchet strap. However I don't skimp on pinning.

I fear though that even if you do manage to secure your joints better perhaps the problem is with the carriage and perhaps packing. Courier companies don't give a Sh*te about the goods they carry, just see how the vans are loaded or talk to a driver they will tell you.

I used to make packing crates and end up paying extra for the size and weight, though last time I needed to send large mirrors to London I go a quote from one of the art couriers it was just as cheap to use them without having to build a crate, so not only would they get it in one piece it was cheaper.

[prospero]

Occasionally you do get the chance to see just how strong your joints are.

I do a lot of repeat frames that take 800x1000mm canvas prints. A 3" scoop with a 1" reeded moulding on the inside. I join these by biscuiting near inner edge, gluing the whole issue up and strap-clamping. The scoop has a nice undercut on the back which makes strapping easy. Once all cinched up tight I take it to the pinner and stack a couple of 10mms near the outer edge. I add a 3" 'L' plate on each corner, under where the biscuit slot is. Then I can fit in the reeded moulding while the glue sets up.

The customer hauls a lot of these around shows and they inevitably get a few dings (easy to touch up as they are hand-finished. ) but now and then one meets with a serious insult. One in particular got caught in a freak gust of wind and went flying along a grass field. Two corners did give resulting in a tiny gap. But even without the glue it was still strong. I filled the gap with cartridge type water-based glue, jamming it as as into crack as I could. Quick lick of paint and good as new. Sometimes it's nice to see your joints tested in extreme circumstances and just how easy it is to fix them.

I did another frame once which was made from absolutely massive moulding. Basically a bit of 4x2 with a few grooves. I used double biscuits and two 4" woodscrews across the corners. Unfortunately one rail was slightly twisted and I couldn't correct it so I decided to break the frame down after it had all set. I couldn't break the corners! Even after taking the screws out. Had to saw it up.

Big area + Tight clamping = tough cookie.

[IFGL]

I use titebond original which I have not had any problems with.

[Not your average framer]

Unfortunately, mitre joints are not one of the strongest wood working joints and regardless what type of glue you are using, the mechanical properties of a mitre joint remain the principle limiting factor. To add real security to a mitre joint, you will need to additional locking features to the joint to prevent the joint from opening.

Fortunately, I have an old fashioned rebate plane and with the fence removed it is a simple matter to pin a piece of scrap wood across the two haves of the joint to guide the plane and to cut a slot to glue and pin a transverse section of wood into the reverse face of the frame at a right angle to the mitred faces. When completed the resulting strength of the joint is quite extraordinary.

Anyone who has not used one of these may be somewhat surprised at how quickly a well set up and well maintained rebate plane can remove a significant amount of wood, as long as it's not oak, which does not plane as easily across the grain unless you have a rebate plane with a skewed blade. I have not got my hands on one of those yet, but a router will still do the job if you don't mind all that dust.

I am slowly getting together a nice set of secondhand planes, to date these are a Stanley model 90 small block plane, Stanly "Bailey" smoothing plane and a Stanley wide rebate plane (the same width as a smoothing plane, but with the blade covering the full width of the body).

The most I have paid for any of them was about £8. All of them came from secondhand shops and they are very useful to anyone who restores old frames! I'm always on the lookout for stuff like this!

[Graysalchemy]

A biscuit jointer does a good job as well on big frames.

[prospero]

I'm just getting to the end of my third box of 1000 biscuits. That's about 750 biscuited frames give or take.

[JFeig]

Unfortunately, mitre joints are not one of the strongest wood working joints and regardless what type of glue you are using, the mechanical properties of a mitre joint remain the principle limiting factor. To add real security to a mitre joint, you will need to additional locking features to the joint to prevent the joint from opening.

Spot on. Nails, screws, splines, biscuits all have a clamping effect as well as a compression support for the finished joint.

Most wood adhesives today are stronger that the actual wood. The proper clamping of the joint during curing / drying is critical.

[prospero]

The thing with frames is the area of the glue surface combined with the length of the rails. If you say, have two cubes of wood with sides 1" and glue them together, you will have a hard time pulling them apart. Extend the cubes into long bits and what you got is a lever. The longer the rails the greater the force exerted on the joint from movement at the other end. I regularly do liners from a 1" bevelled moulding 800x1000mm. These things are very delicate and a slight knock will break the joint. Of course when they are fixed inside a big frame they are not under too much stress so no worries.

Therefore there is a limit to how strong you can make a butt joint.

[vintage frames]

Thanks for all your interesting points. I'm inclined towards the traditional "key" across the back of the mitre which as NYAF says, gives a very strong joint. I'll probably use the router as I've had the most experience with this. The biscuit jointer might even be superior but as I don't own one, it has to be the router.
This is the hazard of supplying only empty frames that don't have the additional support of glass and boards.

[JFeig]

vintage framers
you could always screw in temporary small cross braces in the corners for shipping.

[Graysalchemy]

I think you can getter a biscuit cutter for routers.

[Not your average framer]

I like the suggestion of temporary cross braces for transit. Since it is going to be discarded after delivery, it's not important what it looks like and there's no need to spend too much time fastening these braces in place. Sounds like a win/win to me!

[Jamesnkr]

Put some board in as well as the temporary cross braces. Cost - in comparison with your damaged frames - is near nil.

Mark, any chance of a picture to illustrate; I'd have thought that by using a plane across grain you would be doing horrible things to the grain and end up with a right old mess.

[Not your average framer]

I won't be able to demonstrate how to do this tonight, as my wife and I have to go out shortly. However, I will give a bit more information before going out and make an actual demo corner piece in the next few days.

Record No 050 rebate plane.jpg (185.45 KiB) Viewed 8052 times

This is my Record No 050 rebate plane which I bought secondhand, probably for about £5. Normally it is used for creating a rebate along a length of wood in the same direction as the grain. If it was a dado plane, then there would have been extra blades at each side to make a clean cut to each side of the rebate, when cutting across the grain.

Fortunately you can still use a rebate plane for the same job by sawing the side cuts in first with a fine toothed saw and then allowing the two guide edges at the underside of the plane to locate in the two saw cuts while the plane cleanly removes the unwanted wood between the saw cuts.

At one time, my rebate plane would have been complete with depth stop rods, but they were not there when I bought it. Good dado planes are much harder to find secondhand than secondhand rebate planes. Some dado planes have a skewed blade to improve the action when cutting across the grain.

[Jamesnkr]

Ah, thanks. All is now clear if you use a saw for the edges. A nice piece of kit with myriad uses, though if I've understood you correctly I think you're using it as a plough plane?

http://www.record-planes.com/record-no- ... ion-plane/

[Not your average framer]

if I've understood you correctly I think you're using it as a plough plane?

You may be correct. Although I have heard of plough planes, I know very little about them, so I don't know enough to be sure about this. I did try using the plane this morning and soon ran into problems. I had forgotten that there are two little blades to cut clean edges when cutting grooves. After loosening a couple of screws these tiny little blades can be rotated into postion, but it then becomes very difficult to get the plane to run straight and level.

Unfortunately, I am yet to figure out how to resharpen these two little blades, I thinking that there must have been some sort of fitting provided to secure to the blade to provide some means of holding these blades while sharpening them. Today I decided that it was a good time to get the local hardware shop to order a honing guide and a sharpening stone so that I can get this plane to cut really smoothly and cleanly.

Up until now, I've always managed with sharpening plane blades and chisels with a diamond sharpening pad and getting it about right by eye, but this plane is not as easy to use as I know it should be, so I need to get everything "right", if it is ever going to run as I know it should. All being well, the honing guide and sharpening stone should be available around about the end of the week.

Your info was very informative. I never knew that there were so many different blade widths available. Unfortunately I only have the one blade, which is about 15mm wide. It would have been more helpful to have a 12mm blade, but beggers can't be choosers, so for the time being that's how things will have to be.