need a little bit of help

[red river]

I've got a miter problem on my picture frame that i'm building, but before i do the glue and sawdust trick, maybe someone can tell me how i might fix it or where i went wrong. In the past,  I have made 4 or 5 frames with mitered corners using the jig i made from watching the youtube guy "Woodworking for mere mortals". Jig works like a charm. Miters were perfect. On this frame, I added a 1/4 in and 1/8 in channel along with an inside cove and am going to fill the channels with epoxy resin. As the miter jig works well I'm wondering where i went wrong. Here is the process I used. Had a 2 1/2 in wide 6' long piece of poplar which i cut into 4 pcs. then i ripped each piece to 1 1/2 in wide. On my router table, I then cut my 1/4 in outside channel followed by an 1/8 in inside channel and lastly cut my inside cove. Anyway, my top and bottom rails are the same length as are the sides. The tops and sides are same thickness. I could'nt swear to this but maybe 1 piece is a 1/32 in wider than the rest. i'm gonna double check. I'm wondering if i should have cut my miters first. That gap in the one miter looks like i'm staring into the abyss. Does anyone have any suggestions as to how i might go about fixing this. Maybe i should have made my cuts in a different order? I'm not going to do anything to the frame until hopefully someone replies. Here's a couple of pics of my problem frame and a pic of one i recently completed, which turned out ok. Thanks in advance....forrest 

[Hawk]

Not sure if this will help, but when I cut the 45's on my frames I always do it in pairs, the sides together then the top and bottom together.  I used to use a strap clamp like you have in the picture, but it seemed to always pull the frame out of square. I glue 1 corner at a time in a 45 degree clamp, much better success with that.

For what it's worth, the projects in  your other pictures look great!!

Chris

[JTTHECLOCKMAN]

It is all about accurate set up. First everything must be same dimensions. When you cut the board down to 4 pieces and cut to 1-1/2" wide these must be accurate to each other. You should stand them all next to each other to see if they are truely same dimensions. Then you need to lay them on a flat surface to see they are the same thickness. If that all matches, then your router setup needs to be secure and you route all pieces from the same side. Making sure you keep pieces flat as they pass over router bit. Hold down blocks are good for this when using a router table. After all that then it is time to cut miters and this is where precision is key. You do not show your jig. You do not show what tool you used to cut miters. Never ever ever ever cut miters before doing all mill work first. Something is off and it multiplied 4 times to get that big of a gap.  Take both sides and place them back edge to back edge and place against a straight board so that the top points hit board. Make sure they are 90 degrees to the board and if equal on both top and bottom and then again with the 2 sides, then your angle is off. Need to adjust. Now does the measurements you have need to be that. If you can cut small amount from all 4 corners when you correct the angle then do that and you can save the pieces.  If the pieces are off in any one of the steps will throw frame out of wack. That gap is actually larger than you show because the pieces are not lined up. This same practice applys when doing molding work around windows and doors. 

 

If I may make a suggestion and ditch the strap clamps or any other claps. Use blue painters tape. We make boxes this way and it is a true method of gluing because it does not squeeze all glue out and puts enough pressure on the joints. 

 

https://www.bing.com/videos/riverview/relatedvideo?&q=glue+miters+with+blue+painters+tape&qpvt=glue+miters+with+blue+painters+tape&mid=69988717F634E728105B69988717F634E728105B&&FORM=VRDGAR

Edited August 3, 2025 by JTTHECLOCKMAN

[red river]

Wanted to say thanks to Hawk and JT for the replies. Upon further inspection of all 4 pcs. I saw that the rabbet on the top and bottom rails were not of equal length. I nibbled on the longer one a bit and improved my miter a little bit. I'm gonna go with what i have got will do better on the next one Here is a pic of latest miter and a pic of my 45 deg. jig. The jig looks rudimentary, but I swear it's accurate. JT, I read your reply several times and appreciate the depth of your advice. Somewhere in my process I was'nt paying enough attention to the details. ( my old dad would have said I was half-assing it.) Anyway' thanks guys. To Hawk If i would have stack cut the top and bottom pcs. I could have avoided 2 different length miters...

[JTTHECLOCKMAN]

Those type jigs have alot of errors built into them. So much depends on many things right down to the runners for the miter slots. 

[red river]

Tell me more about these built in errors.

[Bill WIlson]

Have you tried applying sandpaper to the fences on your miter jig?  if the piece moves, even the slightest little bit as he blade is passing through, joints will be off.  The sandpaper will add some grit and make it easier to hold he piece still during the cut.

[JTTHECLOCKMAN]

Errors. Where to begin? Have no idea how you built this so can not comment in those errors. But as Bill said movement when cutting can be a problem. People use either sandpaper on edges of the guides or clamps of some sort. You need to use a stop block to keep piece equal. The runners can have no play at all and yet slide easily. If those rails are not set right, the mistake is multiplied 8 times so just a tiny increment can mean alot in final assembly. There are many versions of good miter sleds on the net. any runout in the saw you are using will add to errors. Good luck with your project. 

[red river]

As far as the sled goes, the construction was good and true to the specs given. The sled has worked well on past projects. However,  I goofed on the execution of making the frame. That's where ya'lls suggestions will help me in the future. Thank you for the replies. I think I may have salvaged the project.

[CharleyL]

It's easy to have errors when building picture frames using mitered joints. The tiniest error can add up and result in one corner joint looking really bad. My dad taught me a trick to pass a saw cut through the offending joint, thereby removing the excess of both pieces to make them fit together better. He used a picture frame clamp, two clamps on a 90 deg base to hold both sides of the frame tightly together while doing this. 

When you cut pieces to make a picture frame, always be certain that the opposite side pieces (top and bottom, left and right) are exactly the same length after cutting. Length is just as important as the cut angles are. Do your absolute best at cutting all corners at 45 deg, and then make them perfect during assembly by clearing the error out with a saw. When you do this, the two pieces will then fit together, even if they aren't perfectly 45 deg. 

I now use a special gauge on my Delta Unisaw, to set the Delta miter gauge at exactly 45 deg, or any other angle needed for cutting segmented circles. It's called MiterSet. With it I can get perfect angle cuts, so if I have an error at assembly, it's usually because the length of one or more pieces is a bit wrong. The MiterSet gauges are incredibly accurate and built with the quality of Aerospace hardware. When I last checked they were still available on Amazon. There are two versions. One is for making angle cuts on segmented circles, like picture frames, etc. The other is for making any angle cut needed in 1/2 degree increments. For square, rectangular, or up to 8 sided picture frames don't buy this second gauge. They both require a 3/4 X 3/8" miter slot and are for setting your existing miter gauge to the angle needed. You don't use these for the actual cutting process. You use your existing miter gauge, but set to the exact angle needed by these gauges. It's quite a pleasure to cut the segments needed for making an 8 sided circle and seeing all of the joints fit together perfectly on first try.

Charley

 

Edited August 9, 2025 by CharleyL

[JTTHECLOCKMAN]

8 hours ago, CharleyL said:

It's easy to have errors when building picture frames using mitered joints. The tiniest error can add up and result in one corner joint looking really bad. My dad taught me a trick to pass a saw cut through the offending joint, thereby removing the excess of both pieces to make them fit together better. He used a picture frame clamp, two clamps on a 90 deg base to hold both sides of the frame tightly together while doing this. 

When you cut pieces to make a picture frame, always be certain that the opposite side pieces (top and bottom, left and right) are exactly the same length after cutting. Length is just as important as the cut angles are. Do your absolute best at cutting all corners at 45 deg, and then make them perfect during assembly by clearing the error out with a saw. When you do this, the two pieces will then fit together, even if they aren't perfectly 45 deg. 

I now use a special gauge on my Delta Unisaw, to set the Delta miter gauge at exactly 45 deg, or any other angle needed for cutting segmented circles. It's called MiterSet. With it I can get perfect angle cuts, so if I have an error at assembly, it's usually because the length of one or more pieces is a bit wrong. The MiterSet gauges are incredibly accurate and built with the quality of Aerospace hardware. When I last checked they were still available on Amazon. There are two versions. One is for making angle cuts on segmented circles, like picture frames, etc. The other is for making any angle cut needed in 1/2 degree increments. For square, rectangular, or up to 8 sided picture frames don't buy this second gauge. They both require a 3/4 X 3/8" miter slot and are for setting your existing miter gauge to the angle needed. You don't use these for the actual cutting process. You use your existing miter gauge, but set to the exact angle needed by these gauges. It's quite a pleasure to cut the segments needed for making an 8 sided circle and seeing all of the joints fit together perfectly on first try.

Charley

 

I will always argue this point about setting any guage to a miter slot. The miter slot needs to be set to the blade. Then anything can be set from it. Many people overlook this. Different ways of setting this depends on the tablesaw. Just my point of view.  

[Wichman]

A couple of points here:

     Tune your table saw. Use your operators manual and online videos to get your saw as perfectly aligned as possible, allow your CDO ( compulsive disorder, obsessive; that way the letters are in alphabetical order, As They Should Be ) to take over and get every adjustment perfect.

     Do not use any type of "thin body" blade, they will warp under stress and cause misalignment of your pieces.

     You are making your own molding, correct? What does your end grain look like, is the wood quarter sawn or not? Are you maintaining the same orientation on all the pieces as they are milled?

     It appears that your molding is "weighted" to the rabbit side of the molding, this can cause the molding to warp slightly and pull the angle out of alignment, you may need to make a micro adjustment to compensate.

     I worked at a production shop making frames and producing wall art for 26 years, a smaller shop for about a year, a smaller still shop for another year and have made my own moldings with a table saw and a molding head cutter. The points I have brought up are things I have had to deal with from sad personal experience.

     At the shop where I worked for 26 years, at one time, had two moldings, both oak, one 2 1/2" wide, the other 3 1/2" wide, one was weighted at the rabbit, the other at the outside edge. To get tight corners I would have to adjust the angle of the double chop saw, both sides, the width of an extra fine sharpie ( .5mm ). When I proved to the boss ( owner ) that it was the only sure way to get tight corners on all sizes of frames ( 8 x 10 through 28 x 40 ) he contacted the molding supplier and had them make a 3 1/2" molding that was weighted at the rabbit, like the rest of the moldings that we used, end of problem and constant adjustment of the machine.

[BadBob]

I have both MiterSets; they are awesome.