Trouble gluing miter joints

[jim gossage]

I am having problems gluing up my miter joints on picture frames. During the test fit using a band clamp, the miters are perfectly closed, and with pretty strong clamp pressure there is no frame deformation or twisting. For the glue up I use tite bond III and rub a thin layer of glue on each miter edge with my finger and this takes about 2 minutes to get them all 8 edges done. Then I add the band clamp and carefully pull the joints together, about another 1-2 minutes. In the end, there is a very slight gap in some of the joints, I assume due to glue film. The gap is uniform so the problem does not seem to be with miters that are 0.1 degrees off one way or the other. What is the preferred way to glue these joints? A different glue? Just coat one side of each joint? Glue 1 or 2 joint first and dry fit the others during clamping, then come back and glue them?

[Mel Fulks]

I would use Tite bond 2, it cures faster than Tite bond 3 , and I use a sharp knife to shave of a bit of wood in the center of one piece
in each corner since the cut pieces often have a ‘high spot’.

After all corners are glued and dried ,I drill holes in the joints and push in a tight nail using a small nail-set.

[glenn bradley]

Titebond III has the highest viscosity of the three Titebond "wood" glues and will therefor require a greater clamping pressure or reduced glue application to achieve a similar glue joint "gap". I use Titebond III for just about everything for ease of supply management. However, I clamp miters like so:
Jan's Frames (1).jpg
which allows a very focused clamping pressure to override the high viscosity glue and I routinely get pretty decent results.
Frame with Inlay (19).jpg
For boxes I use these type of clamps for the same reason:
McLaren Box (16).jpg
and again get pretty decent joint results.
swap-2 (21).jpg
If you want to use band clamps and a high viscosity glue you may consider changing to something like a Merle clamp. These allow a crushing pressure for a small band clamp. I would prefer to use an adhesive with a lower viscosity like Titebond II and / or a more focused clamping method. We all find our preferred way of doing things. Once you find yours you will be able to repeat your results with confidence.

[Lee Schierer]

You are essentially gluing end grain, so you want a good amount of glue. I've made dozens of picture frames ranging in size out of various woods. I use Tite Bond II. I also use a picture frame clamp similar to this, except mine are commercially produced and made of aluminum.
Screenshot_2021-06-08_210835.jpeg

[Alan Lightstone]

You are essentially gluing end grain, so you want a good amount of glue. I've made dozens of picture frames ranging in size out of various woods. I use Tite Bond II. I also use a picture frame clamp similar to this, except mine are commercially produced and made of aluminum.
Screenshot_2021-06-08_210835.jpeg

Lee:

Interesting. I've always used band clamps, but I agree this design looks better.

Which commercially produced clamp are you using? Glenn looks like he is using one too.

[Stan Calow]

. . . Does anyone use cyanoacrylate with longer open time?

Any recommendation on whether to put glue on both faces of each miter or just one?

Jim I wouldn't use CA glue for this. CA is strong in tension, but has no shear strength. So a sharp rap, like falling on a corner, can more easily break the thin plastic layer that CA forms.

I use whichever bottle of TB I have open. I put on both faces - and always use reinforcement, even just the V nails for small frames. And I use the same 4- corner clamp thing that Lee shows. Maybe from Lee Valley, but Ive seen similar from the usual suspects.

[Kevin Jenness]

Glenn's clamping ears (post #3) allow for directing pressure at 90* to the joint surfaces, which is what you want. These can be made up to suit the job, whether boxes or frames, and can be temporarily attached with hot melt or a paper joint. If using a band clamp, make up corner blocks that will put the force where it is needed.

It is pretty much impossible to get a starved joint using pva glue unless there is insufficient glue applied in the first place. Pvas work best with minimal gluelines. Miters may need a double application due to absorption into the partial end grain surface. Fat joints indicate insufficient or mis-directed pressure, old thick glue or the glue setting up before pressure is applied.

[Tom Blank]

Deleted, question already answered.

[Mel Fulks]

Glenn, you sure got some great grain match there , or is that “contact paper” ?

[glenn bradley]

Glenn, you sure got some great grain match there , or is that “contact paper” ?

I will take that as a serious compliment . It is solid walnut outer frame with a 1/2" wide birdseye inlay about 1/8" thick and the inner frame is solid birdseye maple about 3/8" thick. Picture frames can be very basic things and be very attractive as such. Many times you do NOT want the frame to distract from the art. I think that for snapshots it is fun to push the picture frame format a bit and add a bit of razz-ma-tazz.

[John TenEyck]

A bit of a tangent, Glenn, but I just couldn't believe TB III has the highest viscosity of the three yellow Titebonds, but it does per TB's data. That's sure not the way they behave for me though. The behave exactly the opposite. TB III flows very easily while TB Original is much slower to pour, doesn't run as easily, etc. I wonder how TB measures the viscosity? Different methods give different results.

John

[Maurice Mcmurry]

III is also brown which I like for dark wood. For your lovely Maple maybe try Extend, I, or II.

[Jim Becker]

III is also brown which I like for dark wood. For your lovely Maple maybe try Extend, I, or II.

They make a "dark" version of the Type II product...but I have not found it locally to-date.

[glenn bradley]

A bit of a tangent, Glenn, but I just couldn't believe TB III has the highest viscosity of the three yellow Titebonds, but it does per TB's data. That's sure not the way they behave for me though. The behave exactly the opposite. TB III flows very easily while TB Original is much slower to pour, doesn't run as easily, etc. I wonder how TB measures the viscosity? Different methods give different results.

John

I agree. In use TB-III seems to be just about the right balance for me. I guess it would have been smart for me to ask what his material was. Any of us who have had a starved joint can relate to how important this might become. Whether due to not enough glue or not pre-wetting (or sizing) a surface for glue up on an absorptive material like oak, a crushing clamp pressure can starve the joint. I tend to wet the end grain of both surfaces with glue, let it soak in for a minute or so, then apply a "normal" film of glue to one side, and clamp as shown.

[jim gossage]

Glen,
Nice miters, really nice baby!

I didn't know about the viscosity issue. Might have to try TBII. Does anyone use cyanoacrylate with longer open time?

Any recommendation on whether to put glue on both faces of each miter or just one?

Thanks, Jim