Frustration with Nielsen Metal Frames

I've been using Nielsen metal frames for framing prints for exhibitions, primarily because they are less expensive than wood frames and they better lend themselves to re-use. However, I find them incredibly frustrating to put together so that the corners meet perfectly. From the front the corners look fine, but there's almost always a gap at the bottom side of the corner. None of this is the fault of the frame company from whom I purchase the frames - the corners fit together perfectly when I 'dry fit' them before screwing them together. But as I tighten the screws of the corner brackets the corners invariably separate a little and I'm left with a gap.

I've tried all sorts of contortions to hold the corners tight when I'm fastening the corner brackets, but have not found a foolproof way to keep them that way as things tighten up. If there are any tricks/techniques that people use that they'd be willing to share I'd love to hear them. I'm about two f-bombs away from breaking down and buying some sort of clamping device to hold the corners in place while I screw in the hardware

From Amazon.ca.

Well I hate them because I have boxes of them that are scratched up. However have you tried tightening the set screws just tight enough to keep them together and perhaps run a piece of tape side to side and top to bottom while holding the corners in place and then tightening a bit more going from screw to screw until they are all tight enough? It might help. I don't know.

Just remember to check square on any tool that is supposed to hold square before you use it to set something square.

Traditional method is to simply find something with a long straight edge you can set one leg of your square against and draw a fine tight line against the other leg. Flip things so you're set against the edge on the opposite side of your line, and draw another line over the first.

If your lines overlap/cleanly parallel, then you're good to go. If not, then you have some inspection and fiddling to to, if not a return.


As for screwing in hardware I'll second the advice to go slow and only tighten each screw a bit at a time. If you're doing them often enough then rigging up a few larger right angle jigs might be worth the effort to go a step above the previously suggested corner clamps.

Errors compound over distance, and having more distance to align with better shows you the error early.

When I used them I had no issues putting them together with tight fit at the corners. Seems to me that as you tighten up there is a movement derived from turning screws.

As I am looking back some 25 years, it's possible they've changed something in the materials or tolerances. I'd try to insert a thin shim under the screw before sliding the metal corner plates into the frames. Shim will prevent twisting of the screw from applying some movement. Really just guessing a possible fix, as I've never faced this issue.

As a side note, my old issue frames show "track" marks on the underside, they appear to be some sort of measurement scale, and that certainly helps mitigate any sliding tendencies of the corner pieces while being tightened. Not sure if yours show the same clearly intended production marks.

Jigs and clamps are very useful. One “trick” I used to avoid that gap was to tighten each screw loosely at first and then finish tightening in a cross-pattern, like one tightens lug nuts on auto wheels. That way the frame can be racked gently to square the parts up as it’s being built. Then, final tighten only to the point where it is secure and won’t come apart. In some cases where handling may be an issue… drops of nail polish to lock the screws seems better than tighten too much.

Luckless said:

Just remember to check square on any tool that is supposed to hold square before you use it to set something square.

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Unless Nielsen cheated out of high, and prudently so, production tolerances, frame pieces are cut on tightly calibrated machines. They'd be losing a lot of money if they marketed sections not cut to a prefect 45 degree angle.

Hassasin said:

Unless Nielsen cheated out of high, and prudently so, production tolerances, frame pieces are cut on tightly calibrated machines. They'd be losing a lot of money if they marketed sections not cut to a prefect 45 degree angle.

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You’re quite right. Several decades ago there was a knock-off that was sold by some mail order company that did not have very exact accuracy on the angle. The lengths were always right, though. Visually they were indistinguishable from genuine Nielsen except for the inside markings.

MattKing said:

From Amazon.ca.


View attachment 380227

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Yeah, I've been looking at something similar. I might bite the bullet and get something like this.

Back when I used a lot of these frames, I would lay the loose but completed frame sections on a flat, hard surface and use one hand to hold the corner in a way very similar to a corner jig like shown above. When tightening the screws, I found it helpful to tighten one to just snug, then back off a turn. Tighten the other the same. Then switch back and forth between screws tightening just a bit each time. Tighten enough just to hold. Flip the frame over and check the corner. If not right, rinse-n-repeat. Sometimes, I had to do this process 3 or 4x to get the corner right.

Alan9940 said:

Back when I used a lot of these frames, I would lay the loose but completed frame sections on a flat, hard surface and use one hand to hold the corner in a way very similar to a corner jig like shown above. When tightening the screws, I found it helpful to tighten one to just snug, then back off a turn. Tighten the other the same. Then switch back and forth between screws tightening just a bit each time. Tighten enough just to hold. Flip the frame over and check the corner. If not right, rinse-n-repeat. Sometimes, I had to do this process 3 or 4x to get the corner right.

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Thanks. That's essentially what I've been doing, but I'm still not getting the corner as perfect as I'd like. From face on it looks fine, but there is a small gap visible when looking at the side. I might try a corner jig and see if that makes life a little easier.

Of course the YouTube video posted by the vendor makes it look trivial, but they never do show a close-up of the corner once they're done

Hassasin said:

Unless Nielsen cheated out of high, and prudently so, production tolerances, frame pieces are cut on tightly calibrated machines. They'd be losing a lot of money if they marketed sections not cut to a prefect 45 degree angle.

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And I was referring to testing the clamps proposed to hold the pieces while tightening them. Holding two pieces cut to a precise 45 degrees in a tool that does 89 or 91 degrees isn't what I would call 'helpful' if you want tightly closed seams.

Luckless said:

And I was referring to testing the clamps proposed to hold the pieces while tightening them. Holding two pieces cut to a precise 45 degrees in a tool that does 89 or 91 degrees isn't what I would call 'helpful' if you want tightly closed seams.

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Ah ok, my Keyboard and brain did not work together then. My main point is these frames were never meant to need any device to screw them together.

logan2z said:

Thanks. That's essentially what I've been doing, but I'm still not getting the corner as perfect as I'd like. From face on it looks fine, but there is a small gap visible when looking at the side. I might try a corner jig and see if that makes life a little easier.

Of course the YouTube video posted by the vendor makes it look trivial, but they never do show a close-up of the corner once they're done

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A photo of your result would help. What you’re describing is abnormal. A corner jig would help bring wooden pieces together not metal.

And one key point in assembly is to keep the whole frame on a flat surface for tightening, but finger pressure on adjacent pieces should be all that’s needed.

I own Frame Destination selling Nielsen picture frames for over 20 years. It is difficult to perfectly cut picture frames perfectly square consistently even with a $12,000 miter saw and sharp $200 a piece blades. This problem got worse after 2008 when Nielsen seemed to lower the quality a little and the metal seemed a tad thinner and more likely to have some warpage. Since perfect was not possible we calibrated our saws so the slight error would show at the bottom instead of the top which is what you are seeing. Later we upgraded our metal saw to the best in the world (they are around $50K). It is the same saw Nielsen uses and it does a much better job of getting a near perfect cut. The companies using this saw will have the best corners (assuming the blades are sharp) and everyone else will have lower quality. Small custom picture frame shops cant afford saws like this but might order pre-cut from a distrubtor that has one, but not even a lot of distribtuos have the top of thes saws. When I first started out in my garage I used to have top quaity metal picture frames since I bought directly form Nielsen but the minum for each size was 50 units. When I needed to offer more sizes and custom I had to pull the frame cutting in house.

If there are gaps in the corners, they aren't cut square. Unfortunately, that's a common problem even with pre-cut frame sections or too quickly done commercial "chop" services. That's why I bought wholesale bundles of standard 10 ft long Nielsen mouldings and cut them myself.

First of all, you want a small high-quality try square nearby, so you can check if the mitre cuts are actually square or not. Also make sure nothing about the cut is ragged or uneven. Then, in addition, I recommend getting a box of black allen-socket set screws to replace the slotted ones which come with the corner inserts; these can be tightened much better.

Now as per my own gear, perhaps that will give you a few clues to what is involved in a suitably equipped small shop rather than production line. My own mitre saw is an old cast iron one, far more rigid than the kinds of woodworking mitre saws one commonly sees. You don't want any flex in the system whatsoever when the mitre cut is made. One needs to learn the straight-arm technique when pulling the blade down into the moulding; flex your elbow, and you might not get a straight cut in this case. My clamps are also heavy-duty cast material, one on each side of the cut, plus blocking to cut the moulding in exact upright position. Firm clamping is essential. If the moulding gets loose, it can be downright dangerous. Wear a face visor and ear muffs of course. Don't try using a tablesaw!

My blade cost more than the power mitre saw itself, but is true industrial duty, so has needed to be resharpened only once in 40 years. For more casual use you don't necessarily need a blade that expensive, and can find something appropriate for around a hundred dollars. But it has to be specifically for thin section aluminum (non-ferrous) cutting, with the right negative rake angle and carbide tooth count. Using any kind of ordinary woodworking blade, even high tooth count, is dangerous and will produce a ragged cut. Also use an appropriate cutting fluid each instance.

You also need a good length stop system which will keep the moulding level at precisely matching lengths. The INTERNAL length should be slightly oversized (about 1/8 inch) to accommodate any expansion/contraction stresses of acrylic glazing as well as matboard and backer board.

fdi - Thank you for bringing to attention the amount of investment needed to do this well on a production distribution basis. I hope you've read my tip about substitute Allen socket-style corner screws; it makes life a lot easier. Sad to hear about the decline in Nielsen metal quality; but that kind of issue is an all too predictable trend these days. I probably have enough lengths of good ole material on hand to drift along at my now elderly pace, unless another big show opportunity arises.

Yeah Drew you pretty much figured it out. Yes clamping is the key for cutting metal picture frames. The problem with the $12K mitre saw is they do not clamp close the cut and the clamps are pneumatically held in place when the saw goes down and when it comes back up. Once the frame it cut it is no longer being clamped on both sides and can move just a little when the blade come back up. It is best if you can actually pull the metal back away from the blade before allowing the blade to come back up then you know you wont have two cuts. Our really high end saw is fully computerized and the blades actually cut into the clamps so the metal is clamped all the way to the blade. I am not sure why but in addition to us being able to have super accurate length so the pairs are actually the same, but we dont even have to de-bur the metal after it is cut. On the old saw if one of the sticks was damaged we would have to cut a pair to ensure they were exactly the same length (assuming the stop was moved since they were cut) since the stop was set by a human using his eyes to read the ruler.

Traditionally big air mitre saws with pneumatic clamps were used for this; but the clamping systems I've seen weren't ideal. I happened to set up the first Makita retail display in the US, back when all their tools were true industrial quality, and even had several power tools designed or re-designed to my own specs, including their last high-end Japanese made smaller mitre saw (no longer available). I was also directly involved with the design and marketing of the deluxe Festool slide saw (which is great for the finish carpentry trade; but I can't recommend it for aluminum picture frame moulding).

It doesn't take much to get a messy edge. A single bad tooth on the blade might do it. Industrial blades are typically much higher quality carbide than construction blades, not to mention the distinction in rake angle and grind pattern. But we sold all kinds of carbide too - during my time, the largest Freud dealer in the US. I'd have to go to my shop to see exactly which blade lubricant I use; but it's spray-on water-soluble, so easy cleanup.

I like the concept that your mouldings are well supported from vibration right up to the saw kerf on both sides. I do that by means of beveled hardwood strips held in really tight by the big adjacent cast iron clamps. But my own method would be way too slow for your own high production capacity. Thinner Nielson profiles like no. 33 can easily vibrate and get a ruined cut unless very tightly clamped on both sides of the cut.

One more thing for those doing their own cutting with conventional electric mitre saws : after slowly and carefully plunging into the cut, clear-through consistently, then allow the blade RPM to fully wind down before retracting the blade back up. With all but the very best quality electric mitre saws, the motor spindle is likely to have more wobble than is ideal for this purpose, and might cause the blade to bump along your freshly cut edge as you retract it, if it is still spinning. And yeah - I tested just about every brand out there at the time in an engineering focus group.

My own 10 inch blade was made by Nordic here in CA, a really high-end custom supplier, and it's nice and thick and rigid, ideal for the purpose; I got a good deal on that because our own mill and door shop used their blades up to 22 inch diameter (now those cost a lot!)

The idea of using Allen-head set-screws is brilliant. I don't own a thread gauge - what's the threading?

I have seen different threads, depending on whether the corner pieces came from Nielsen or some picture framing distributor who sold interchangeable corners of their own in bulk quantity. I'll have to check out in the shop. But the threads are necessarily fine - probably 10-32. 10 gauge screws are nominally 3/16 inch diameter.

The most annoying thing when assembling each frame corner together, and loading in the picture sandwich, is when something slips because the corners aren't really tight. Being able to tighten things down well with an Allen wrench alleviates that issue (I use a hex tip on a magnetic hand screwdriver).

I also attach Hangman aluminum cleats that way, using set screws, to the rear upper profile of the moulding. It's a lot more elegant solution than ordinary wire, and won't shift on the wall.