Help Needed with Miter Joints

[BrianBDH]

I am using some teak moulding to make a small picture frame (roughly 8 x 12). Previous projects involving miter joints were painted, so copious use of caulk was standard. But in this case I want to use only Tung Oil on the frame, maybe a little poly to give it some gloss.

I cut the pieces using my miter saw which has a stop for 45 degrees. Since I don't have the best clamps I used my table saw to put splines in each corner. After everything is glued up, I have 3 very nice joints and one that has a hairline crack (a thick hair).

I need some advice on the best way to try to hide the crack.

I could take some teak dust from sanding, mix it with glue and put it in the crack. But I don't know what color this will be after I apply the Tung Oil. I guess I could take some scrap and do a test case to see what happens.

I could go ahead and apply the Tung Oil and then take it to the hardware store and try to find a filler that matches the final color. But I don't really want to spend a bunch of money for a large quantity of filler that I will probably never use again.

Do any of you finishers have a trick you could share with me?

Thanks in advance.

Brian

 

[BenBen]

What I've done on small hair-line gaps is after I sand the entire piece overall, I put a line of wood glue over the gap, sprinkle over some sawdust of various size, anywhere from fine to bigger pieces, and rub this together over the gap with my finger. I let it dry maybe a few minutes (the rubbing of the glue speeds this up as well), then hit it with my ROS. I do most of my work with walnut and it has worked well with walnut.

 

[smitty62]

My experience with any dust/glue mixture is it dries too dark in color for lighter woods--but ok for walnut, etc.

 

[Travis Porter]

Going forward, you need to perfect your miter cuts and clamping methods. You don't have to have "special clamps to glue them up, nor do you need a high dollar set of tools.

When cutting your miters, you should not move the saw from the position you start with. Rotate your stock around the saw, but don't move the saw. Even if your saw doesn't cut a perfect 45 the two sides together should equal 90 and that is what you are wanting.

For clamping, you can make up some corner pieces that allow you to hold it together with regular clamps in the middle.

For your gap, it is going to be tough..... I would probably go ahead and finish and then try to match some wood putty like you get at the BORG that has different colors to match. Probably buy a couple of cans so you can mix your own.

 

[MarkE]

Another thing you may want to try. Take some fine shavings off a piece of scrap with a hand plane and push them into the crack with a razor blade. You can get glue into the crack under pressure or just put a small amount of glue on the crack and work it into the gap with the razor blade or a piece of paper.

I have used this method on some cherry with pretty good results.

 

[BrianBDH]

Travis,

I don't disagree for one second that I need to work on the technique. I'm not going to whine and say these pieces of moulding are pretty crooked too. I found a thread for a miter sled that looked easy to build and would probably improve the quality of my joints tremendously.

I didn't want to keep moving the saw back and forth from 45 one side to the other, but the moulding was nearly flat on only one side, so that side had to be down always. The only way to make a mating cut was to move the saw.

Here is a question for everyone. I'm sure you are all familiar with pocket screws. I have used them in a lot of 90 degree frame joints. They do a great job of pulling the pieces together to form a really tight joint. If I could have found a way to use them here to pull the joints tight, I would have. But the profile of the back side (with a fairly large rabbet) would not allow me a way to get my jig clamped on securely.

Anybody know of a similar fastener that can be used to pull the corner joints tight?

 

[Travis Porter]

I have seen some spring clamps that go around the outside that work.

 

[4yanks]

Between coats of finish you could apply a darker glaze. Wipe the glaze off from all of the surfaces but allow some to stay in the creases of the molding and in the corners. This will hide your hairline crack and give all 4 corners a uniform appearance.

 

[James Davis]

Have you glued in the spline? If not, you could "kerf in " the joint. Take a fine cutting hand saw (Dovetail or the like) and make a cut along the open miter. That way you take a little off of each side of the opening and the resulting joint should be tight since it was made in place. Even if you have installed the spline, you might could run it back through the table saw and remove the spline and still kerf it in and then you have 4 tight joints and no need to look for filler or fixes that may or may not work.


James

 

[Sully]

Have you glued in the spline? If not, you could "kerf in " the joint.
James

I was going to post the same suggestion. It will not remove much material and should tighten up the fit.

J

 

[BrianBDH]

Great suggestions from everybody. First, the splines are glued in. No, I don't have a fine handsaw.

Since this is just a project for me, I am probably going to give a try to the glue and dust solution first. But I am going to try with yellow Titebond and with white Elmers to see if it makes a difference in how they take the Tung Oil and the final color.

If I don't like the result, I can start over and turn these pieces into something else. What dimensions do the pen turners need to start with? Would a couple of Teak blanks be of interest to anyone?

 

[Trent Mason]

Brian,

If you're going to go with the glue and sawdust approach, I'd use CA glue instead of Titebond or Elmers. CA glue is clear, so the only color you'll see is the sawdust. With wood glue, you might see a lighter color once it dries. Just my .02

 

[FredP]

what travis said. as to the gaps? there are some design mods that work and enhance the frame a little. the easiest is to make a router jig and route a shallow channel at each miter then ad a strip of contrasting wood.a little hand work at the inside corners and sand the outside corner and the face flush. :icon_thum not a frame but the principal is the same.

 

[Glennbear]

Great suggestions from everybody. First, the splines are glued in. No, I don't have a fine handsaw.

Since this is just a project for me, I am probably going to give a try to the glue and dust solution first. But I am going to try with yellow Titebond and with white Elmers to see if it makes a difference in how they take the Tung Oil and the final color.

If I don't like the result, I can start over and turn these pieces into something else. What dimensions do the pen turners need to start with? Would a couple of Teak blanks be of interest to anyone?

FWIW in a pinch a few times I have used a hacksaw as a thin bladed wood saw. :wsmile:

 

[MrAudio815]

My experience with any dust/glue mixture is it dries too dark in color for lighter woods--but ok for walnut, etc.

+1

Actually I had some small cracks in a walnut bowl I am turning and put the saw dust in the crack and it dried darker than the walnut. :eusa_doh:

 

[Scwood]

I know this is too late too help you,but when gluing teak wood you need to clean all the glue area with acetone first.The acetone will get rid of all the oils near the surface so the glue can take hold.
To fill the crack you have now you could get a little jar of Famowood or Goodwood filler for just a few bucks.

 

[Joe Scharle]

Pocket screws work well on large frames if the front side has enough 'flat' to maintain alignment. But I've found that Merle band clamps from MLCS are my favorite for frames. These clamps have steel bands and don't stretch. Add corners and clamp 4 to 8 corners easily.

But the 'trick' to frames is still exact angles and lengths. A sled like this will make it all so much easier.

Using an adjustable Right Triangle to set miter angle. NOT the cut side!
View image in gallery​

 

[Mike Davis]

Picture frame shops use wax crayons in special wood colors to hide nail holes and cracks.

 

[erasmussen]

I little late now, but you can use a shooting board to get tight miters