I am looking for a corner reinforcement fastener for miter joints. We used to be able to get these readily, but I can’t find them anymore. I have done a Google search under every descriptive name I can think of and come up empty.
The device looks like two dowels joined at right angles (as though they each have a miter cut and are joined there). But it is one molded piece. It’s made of plastic or metal-filled epoxy. They come in various sizes. We used to get them 1 inch or 1-1/2 inch long on each side, 1/4 inch diameter.
For joining a picture frame, miter joints are cut in the frame pieces and holes are drilled in the long direction of the frame pieces through the face of the miter cuts to accept a fastener at each corner. They bond well with wood glue or epoxy.
Has anyone worked with these fasteners? Do you know a source of supply?
Thanks,
VL
Edited 10/19/2003 2:26:40 AM ET by Venicia L
Replies
If you find a source, Venicia, please post it here! Sounds like something I could use for sure. Have you tried calling some frame-makers to see if they know of a source?
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Forestgirl,
No, framers are completely unaware of such fasteners. In fact, this all started as a result of my attempts to show a good friend who is a "master conservation framer" some "proper" joinery techniques.
Framers routinely join frames with glue on the face of 45 degree miter joints thinking such a joint is secure. They use "V-nails" across the joint on the back of the frame after allowing the glue to "set" (usually in 15 minutes).
I am amazed that my friend who is very knowledgeable about her craft has no understanding of the mechanics of a glue joint. I've challenged her that the joints she is making are being held by the V-nails and almost nothing else.
I'd like to find the fasteners that I described because they would make a much stronger joint. I'm almost sure we used to get them from Garrett Wade, but I can't find a trace of them anywhere.
I'm putting together some jigs to produce a compound miter/finger joint or miter/mortise and tenon joint which creates a mitered corner, looking at the front of the frame, but a meatier joint for most of the rest of the wood behind the frame face.
VL
http://www.hoffmann-usa.com/htm/keys/dovekeys.htm
I have a friend who uses the Hoffman dovetail joining system.
Think I might still have a magazine that was dedicated to professional picture framers that had all kind of suppliers listed.
Might be this one
http://www.pictureframingmagazine.com/
Migraine,
Wow, those look good. I've never seen that type. The kind I used to have were simply a continuous moulded piece fixed at 90 degrees.
Rick,
Thanks. Those supplies are typical framers' ware.
VL
I did another search, but spelled it "mitre" this time after seeing the title on the last post. Bingo!
Here's the product - it's hard to see on the web page:
http://www.siso.dk/products/products1.asp?ID=189&products=ok
And here is functionally the same thing:
http://www.ebcofittings.com/products/joinery_fittings/mitre_joint_connector/mitre_joint_connector.htm
VL
Thinking into the future, I'd prefer a flat 90 deg flat bracket either screwed to or rebated into the back of the frame. Come the time to disassemble the frame, you can see the metal and thus avoid damage to your tools.
Ian
Ian,
Yes, A flat connector (rectangular or square cross section) would also facilitate glue-up as it would help prevent the frame members from twisting. I had contemplated making such connectors by cutting them from aluminum or brass stock. I had also contemplated making them out of some strong moulded fibrous, plastic or wood product. I may still do that.
But I would rather not have to fill the the back of the needed routed slot or otherwise have evidence of the mechanics of the joint visible on the back of the frame. It has to do with the esthetics of the particular kind of frame I'm designing.
I hadn't described that, but the design involves a back completely closed with a (slightly) raised panel in a frame and panel arrangement. This is unusual for even conservation frames which are closed in back with paper glued around the perimeter (crude as far as I'm concerned).
When I get some frames built I'll post some pictures. (If I can figure out how to upload to this site)
I may still use "flat" connectors, but as far as disassembling frames, that's almost never done.
VL
Venicia,
If I'm following, you want a rigid connection across the joint. have you considered using dovetail keys? If the back is to be closed with a panel, this panel will hide whatever you use to reinforce the joint. Go for a fastener that's easy to install.
Ian
Ian,
Thanks. Dovetail keys are certainly possible if the mating faces have enough room. Some frame designs are very tiny in the joint thickness.
Anyway, the design is proceding.
I'll eventually have some images to post.
VL
Venicia, if you're contemplating a solid back panel in the frame, you could adjust the design and make use of the panel's rigidity to reinforce the mitre.
Ian
Ian,
The back is not rigidly attached to the frame. As in all frame and panel construction, it has to float to accomodate the wood's movement.
Also, the back must be able to be removed if necessary to get to the artwork. So the frame must be able to exist on its own. In my design, the back is the equivalent of the bottom in a classic drawer construction. The back rides (fairly snugly) in slots in the frame and is "pinned" in the closed position. It seals the whole affair against dust and vermin but opens when necessary - clean as you please.
In typical frames, opening the back means cutting away the paper (which has probably already been damaged anyway - I don't know how anyone has accepted this kind of shoddy work for so long) and removing the gummy mess all around the perimeter where it was glued.
VL
Venicia
you seem to want to go to a lot of effort with your frames. For the rear panel I suggest you use plywood tacked into a rebate. It wont move a dam with changes in humidity and if you pin it to the frame at the corners the panel will also reinforce your mitres. If the panel is in a groove, the frame will need to be disassembled to get the panel out. However, I'm leaning more and more towards a flat 90 deg bracket screwed to the back of the mitre to reinforce the joint, they're readily available and can be recessed by their thichness into the frame if you want.
Ian
After this discussion goes on awhile I'll explain a number of reasons trained picture framers don't use wood as a backing material in serious framing.
Corners. Yes. Please.
When I went into this project I kept asking myself why the practicies that I have found crude have persisted. And why techniques that appeal to me as a furniture maker may be disastrous in this eneavor. I have wondered most about the backing solution. Other than weight (not a significant problem), why I wondered, have I found no frames built with a closed back?
There are many furniture makers who don't finish the back of a cabinet which is designed to stand against a wall. They exist and will continue to exist. But a good deal of the satisfaction I derive from my work is the delight the recipient of any one of my pieces expresses to find that every surface that can be touched or seen is finished.
The corner mitre reinforcement problem is pure mechanics and I think I can see where that is leading me. And it continues to be in the direction I have taken. I continue to find the all-prevalent V-Nail practice (and similar methods), crude. Effective? yes. Quick? Yes. Cost-effective? Yes. Satisfying to me a a craftsman? No.
My hope in posting here was to get advice from others about something I could not see for myself.
VL
Ian
"However, I'm leaning more and more towards a flat 90 deg bracket screwed to the back of the mitre to reinforce the joint, they're readily available and can be recessed by their thichness into the frame if you want."
Yes. The final design is moving more toward that solution but not quite in the way you're describing.
I'm using both a plywood back panel and a glued up solid panel. As in all things, each has advantages and disadvantages.
VL
The Ebco fitting doesn't look like it would be absolutely rigid, a characteristic that you'd seemingly want. I swear I've seen something in the past like the plastic ones you refer to. Must be someone in the US that sells 'em!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Forestgirl,
Siso refers to the fitting as "knockdown." That's a worry. The kind I am looking for are glued in place. Super strong.
I can't tell if the Ebco model is hinged or not.
This is such a simple and effective device. It's amazing it's such a mystery item now.
I'll start making inquires at Garrett Wade and Rockler tomorrow to see if they can get them, or if I have to go directly to the manufacturer.
I made 16 frames today to accept one or the other type. I better be able to get them!
I also tried making a square cross section connector by using 3 small brass corner braces stacked one upon the other. I aligned them very precisely, clamped them tight and soldered them! It was very easy to do. I abraded all the surfaces with 320 grit. Used a torch and solder from Radio Shack. When they got hot enough, the solder flowed inbetween the pieces like a vacuum was sucking it in. It's a very neat little stacked connector. It's solid!
Who knows, maybe I'll go with that! I'll epoxy them into routed channels in the frame pieces.
VL
Edited 10/20/2003 1:15:02 AM ET by Venicia L
"Siso refers to the fitting as "knockdown." " -- that's before you put the epoxy in, LOL.
"I can't tell if the Ebco model is hinged or not." Some other picture(s) I saw when web-searching seemed to indicate that it is hinged. That's how it accomodates all those angles. I just wonder if it might lock somehow....
Good luck, keep us posted!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
To be able to design a suitable miter joint a few questions:
Thickness and width of the sides, top and bottom members.
Type of wood.
Size of the frame.
Weight of the frame and the load it is to carry.
Method and hardware used to hold the load in the frame.
Will the future use of the frame be dynamic or static - for example will it just hang on the wall or perhaps be a door often in motion.
Hanging technique, hardware to be used, and how is it attached to the frame.
And a few more thoughts - why so much reliance on hardware? How about cross miter splines or a laminated closed corner or even a couple of pocket screws?
Venicia,
I believe Rockler used to carry those. I took a quick look in the current catalog but did not see them. It might be worth a phone call to their product information staff 1.800.260.9663.
jk
I used exactly these same "devices" about 25 years ago and have some left in my parts bin. They are white plastic, at 90 degrees, and have ribs every so often. I'm sure I got them mail order, and back then the only place I was aware of for mail order was Constantine's. They probably were my source.
However, I'm wondering if making a miter joint with a hidden spline might be stronger and simpler. I'm thinking here of a spline where the grain runs perpendicular to the grain of the frame sides. I think it'd hold just fine and with the cross grain it'd be much less likely to "snap" along the glue line.
Your thoughts on this approach?
John
John and Corners,
The application is picture framing. The problem with picture frames is that the mitered surface is often of precious little area because of the shape of the moulding and the rabbeting to hold the artwork.
I need to upload a few drawings. Splines are good for frames that are wider than deep. But deep frames would do better with the method I'm after.
The major problem with a spline is that it intrudes across the inside corner and must be trimmed. That's hard to do after the fact. The spline could be prepared with a notch but that's more assembly work for the framer.
Picture framing is a production line kind of custom work. Time is money and the framer MUST be able to produce. That's why many of the techniques have developed that I find crude. Nailing V-nails into the back is quick and apparently "good-enough to have become the standard.
My design will probably be called overkill by the typical framer, but it will meet my demands that it be a piece of fine furniture. And I think I can make it as fast or faster as the cheapo methods.
After-all, the cost of a 20" x 30" frame hanging in one's living room can easily be $800-1000. Larger frames can easily cost $ Thousands. Framers justify this by explaining that it protects even more expensive contents and can be expected to last a lifetime. For $1000, an end table in that room better be finished as well on its underside as on top! Imagine securing the table with nails and gluing paper to it's back as the finishing touch!
My design also addresses the wire hangar, its attachment and the transfer of forces.
It'll be a few weeks, but I'll get some images posted here.
VL
Venicia, I continue to be intrigued by this thread. My one and only semi-commercial item at this point resembles a very large shadowbox, for sports apparel display. I'm curious, what drilling procedure would you use to ensure that the holes in adjoining members line up perfectly in both planes?forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Forestgirl,
When I had a supply of the connectors I'm looking for, I also had a horizontal mortiser which was on an Inca table saw. It was easy to bore the holes with that.
I no longer have the Inca saw and I've been thinking of constructing another horizontal mortiser with a router. I may end up just using a hand drill clamped to a sliding jig. It's not hard to accurately index the holes with spacer blocks. The back of the frame piece is a constant index in one plane. The piece is turned end for end and moved the proper distance in the second plane with spacer blocks.
Again, I'll post some pictures in a few weeks when everything is set up. I need to keep it simple to appeal to a framer who is used to working very quickly with a set of other habits long established.
One of the frustrations framers face is that miter (mitre) joints twist in 2 directions and slip and slide like crazy with glue on their faces. They usually opt for gluing one joint at a time in a miter vise. That invloves gluing each, waiting for the glue to set, gluing another, etc. They put the V-nails in after the joints have all set. I don't know why they don't nail them while each joint is in the miter vise. They roll their eyes when anyone suggests a four-corner strap clamp. They've experienced that pain!
With the right-angle devices in place, four joints go together very easily with a four-corner clamping system. The glue-slippery miter faces which were the source of the problem without the connectors, slip and twist right into perfect alignment and the whole frame assumes a single plane (if the joints are acurately cut).
VL
Suggest you find a more experienced framer to talk to. There are many ways to join a frame. Strap clamps are a hassle - 4 bar clamps will pull a difficult corner into line much easier. A skilled framer puts the glue on the miter, places the pieces in an automatic machine which aligns the parts and clamps it before driving in a Vee Nail which is designed to pull the joint together. A suitable number of nails are inserted for the size moulding in use and the frame is put aside for a few hours for the glue to reach some strength.
Here's an other example of one frame joining system - there are many of this type including systems that have this router plastic insert joint built into an automatic double blade miter saw which cuts the joint and routs the slots at the same time.
This one is American made: whereas the combined saw type is Italian.
http://www.fletcher-terry.com/fletcherterry/ecatalog/viewfamily.jsp?level=4&parent_id=128&parent_id2=5&tl_id=5&family_id=22
Corners,
Thank you very much. Now THAT is a way to join mitre joints. I have no doubt it is an excellent method. My friend is not aware of that equipment at all. She is very, shall we say, "old school."
The method I want to use is (at least to me) more pleasing esthetically. I can already do the job with a router and no specialized bit. I can't get the idea across in words any better than I've already described it. I hope I can show you when I've put some frames together and the jigs and holders.
On the other hand, what I'm attempting may be an exercise in overkill and frustration. We'll know in a few weeks.
VL
"slip and slide like crazy with glue on their faces." -- why not use hot hide glue and perform the "rubbed joint" technique? I'm eager to try it myself (and now that it's raining a couple inches a day, should get back into the shop soon!)
The Beadlock web site shows their product being used in a miter joint. Go to the bottom of this page: http://www.beadlock.com/projectapplications.html
Might not be a bad idea. 3/8" is the smallest they make though. Sorry to keep yabbering at you like this -- bet you'd like to get to work!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Forestgirl,
Hot hide glue is my favorite type, for almost anything. What is the rubbed joint technique?
VL
I first saw the term "rubbed joint" in an article by Dresdner re: hot hide glue and its advantages. Asked a few questions here, and evidently you can apply hot hide glue to both surfaces and simply rub the joint together for a few seconds, then let it sit for a bit.
Check out Post #3 in this thread to see Napie's report on joining frames:http://forums.taunton.com/n/find/findRedir.asp?webtag=tp-knots&mg=DDB02905-9831-47DD-9EEF-DBC5BBAE5E48forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
You may find this website interesting:
http://www.holtonframemakers.com/mirrors/specialty/Ashbee.html
And this one:
http://american-choice.com/index.html
One more - a high end frame source - many of these frames are refered to as "closed corner" there are no miters as they are built up on a strong frame which doesn't show in the final product.
Corners,
Some of the Holton mitre designs are usable. For very small cross section frames and the prevalent "veneered" frames - no. Mine will work with those.
Anyway - The suspense is too much to tolerate - what is the reason that the backs of frames are not closed with a panel?
VL
Most picture framing involves items of paper or fabric. Old paper and fabric doesn’t go brown because it’s old – it goes brown because acids are attacking it. Wood is acidic. Go to an antique shop and open the back of an old art print on paper with a wood backing – you will see a black mess. If the print also has an old wood pulp mat you will likely see another dark mess on the front.
Modern framing techniques work to conserve or preserve the item being framed. For example mats were first used to separate the art from the glass to stop problems of glass/condensation interaction with the art. Mats eventually became decorative as well. Modern mats are made of wood pulp with the wood lignins removed or of cotton. The backing boards are also made of these safe materials. Wood is not accepted close to the paper or fabric being framed. In high end framing even the frame rabbet which is quite removed from the art is sealed with a foil tape.
The risk of future damage to the framed item generally precludes the use of a wood backing.
A common backing board within the frame is coroplast, a rigid, inert corrugated board.
As for the paper dust cover on the back of the frame, it can be well done with a thick, non acidic paper such as Lineco brand. It just has to rest against the wall without damaging anything for 100 years or so.
Corners,
I know I have to tread a little lightly here. My knowledge of woodworking is fairly good and I can speak with confidence about a fair number of issues. But I'm a novice regarding conservation framing and I may just be missing something as obvious as the nose on my face.
So, with all respect, I just don't buy this one. I can grasp the principles. There's no rocket science involved. Keep the artwork from contact with any acid-containing material. The work is mounted on acid-free board, the mats are acid-free, the materials backing the mounting board are acid-free. Adhesives and mounting hinges are acid-free. And the back of the frame is closed with a sheet of paper. At some appropriate time in the future, the whole assembly is opened up and fresh mounting and matting is done because air polution can bring destructive acid-containing impurities in.
Now, even in conservation framing that backing paper is not always acid-free. It certainly can be. But if it's not, the framing can still be called "conservation." Why? Because the paper sealing the back can never come in contact with the artwork.
Something hardly touched on among all the dire warnings that lignins and wood products must not be in the mounting materials is that the pristine, acid-free mounting assembly of artwork, mats and mounting boards is encased in and surrounded by a wooden frame! Often a softwood frame (veneered with a microscopic skin of some exotic hardwood). The worst kind. With no sealer or other impediment to outgassing of all kinds of nasty chemicals.
I simply cannot believe that the presence of a wooden back would change the internal environment of the frame in any significant way.
I realize at this point that I had never mentioned that I never planned to use anything but hardwood in my designs. I didn't anticipate finishing the rabetted inside surfaces of the frame members, but since the back of the back piece will be finished, I do plan to finish the inside of the back since I will need to balance the very thin panel.
What am I missing?
VL
You are simply missing the accepted modern standards of a well established industry which has reacted to it's past and looks to a safe future.
Picture framers of the past did the damage and conservators of the present created the techniques for partial recovery. Now framers and conservators have joined to provide techniques for a better future where far less recovery will be needed.
The frame is not as important as the item being framed in most cases.
Use your own judgement but be willing to hear other opinions and when the emotional, historical, and/or monetary value of an item being framed causes you to hesitate because you are not fully confident in your practices be ready to accept new ideas.
But build a beautiful frame!!
Corners,
"But build a beautiful frame!!"
Yes!
My aluminium design is also coming along quite well. Now THAT's going to be an "inert" surround for the precious contents.
VL
Hmmm, now I'm beginning to understand. Let me suggest another approach. There's a company that sells a device which can be used to bore dowel holes that overlap and are used for floating tenons. I'd think that if you used this to create a two or three hole (overlapping, of course) mortise that the floating tenon would be much stronger than the plasticy things that we've both used in the past.
Give me a second and I'll come up with the name and edit this post with the company's name.
Edit ... the company's name is Beadlock.
John
Edited 10/20/2003 6:55:39 PM ET by johnhardy
While I doubt if all you do is picture framing that these would interest you, for anyone else reading the thread for good gouge on miters, check out http://www.miterclamp.com. They're called clam clamps, they're invented by and geared for trim work. I'll vouch for some amazing pulling power.
"The child is grown / The dream is gone / And I have become / Comfortably numb " lyrics by Roger Waters
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