Replacing brass wood screws with machine screws on an antique camera...

[fecaleagle]

All right, after overhauling a stripped out Speed Graphic with hardwood dowels and one size larger screws, I'm looking for some opinions on an upcoming project. I just acquired a 5x7 Agfa/Ansco from the late 20s/early 30s. The wood seems very solid, but as I'm going to be replacing the bellows and cleaning everything up, I am going to want to remove a good number of wood screws to clean up the hardware. I have already noticed a handful of screws that seem to have stripped out their wooden holes. I am toying with the idea of drilling out the stripped (possibly all) of the screw holes, inserting machine screw inserts, and replacing the original screws with machine screws.

Has anyone around here done this before, and if I should proceed, what caveats do I need to be aware of?

Thanks,
William

[ic-racer]

Unlike woodscrews, the machine screws in metal inserts may loosen without lockwashers or thread locker. The screws probably won't loosen during use, but if the camera rides around in the back of a vehicle or plane, it could be an issue. The metal inserts could also pull out. I'd stick with drilling out the holes and putting wooden dowels in the holes.

[Drew Wiley]

You can fill the hole with a type of paste epoxy specifically intended as a wood sustitute.
Drill a pilot hole as needed, and put the original screw back in.

[fecaleagle]

I suppose it's not as critical here as it was with the Speeder (focal plane shutter panels that I needed to be able to remove occasionally to make adjustments) to be able to remove and replace them from time to time. I think I may go with the machine screws and thread locker, but the paste epoxy sounds like a good alternative for the screws that I will not need to remove more than every 20 years or so. For instance, the screws that hold the back on are something I'd like to be able to remove regularly without any additional wear on the wood.

Thanks guys.

[Jim Jones]

I usually apply epoxy to the hole in the wood and to the external threads of machine screw inserts before theading them into wood. Don't apply too much.

[Sevo]

I usually apply epoxy to the hole in the wood and to the external threads of machine screw inserts before theading them into wood. Don't apply too much.

As in "glue in the screw"? Don't do that unless your intent is to make any further repair impossible.

The wood filler (use dedicated wood filler, not some generic glue) should have completely hardened before you drill a new hole and insert a new (or the old) screw.

[E. von Hoegh]

All right, after overhauling a stripped out Speed Graphic with hardwood dowels and one size larger screws, I'm looking for some opinions on an upcoming project. I just acquired a 5x7 Agfa/Ansco from the late 20s/early 30s. The wood seems very solid, but as I'm going to be replacing the bellows and cleaning everything up, I am going to want to remove a good number of wood screws to clean up the hardware. I have already noticed a handful of screws that seem to have stripped out their wooden holes. I am toying with the idea of drilling out the stripped (possibly all) of the screw holes, inserting machine screw inserts, and replacing the original screws with machine screws.

Has anyone around here done this before, and if I should proceed, what caveats do I need to be aware of?

Thanks,
William

I'd eschew the machine screws. Drill out the stripped holes, epoxy some hardwood pegs in, sand flush, and re-use the original screws.About the same amount of work, and a more proper result.

[rdenney]

As in "glue in the screw"? Don't do that unless your intent is to make any further repair impossible.

The wood filler (use dedicated wood filler, not some generic glue) should have completely hardened before you drill a new hole and insert a new (or the old) screw.

No, he was talking about gluing in the insert, which is a very good idea. The idea is that you are making a permanent repair.

Another option for screws in flat panels where you have access to the backside is a t-nut. McMaster sells them in stainless steel down to 10-24, and in plated steel down to 4-40. The screw locks these in place and they will not loosen over time.

It seems to me that doweling or filling wood will be less strong than the original screws, which, at least over the long run, were obviously not strong enough. If you drill and screw into an epoxy plug, be sure to use exactly the correct pilot drill--epoxy has little tensile strength and can split. Gluing in a dowel and retapping is good preservationist practice, but do you want to use the camera or preserve it?

Rick "who has repaired a lot of worn screw holes, just not in wood cameras" Denney

[E. von Hoegh]

No, he was talking about gluing in the insert, which is a very good idea. The idea is that you are making a permanent repair.

Another option for screws in flat panels where you have access to the backside is a t-nut. McMaster sells them in stainless steel down to 10-24, and in plated steel down to 4-40. The screw locks these in place and they will not loosen over time.

It seems to me that doweling or filling wood will be less strong than the original screws, which, at least over the long run, were obviously not strong enough. If you drill and screw into an epoxy plug, be sure to use exactly the correct pilot drill--epoxy has little tensile strength and can split. Gluing in a dowel and retapping is good preservationist practice, but do you want to use the camera or preserve it?

Rick "who has repaired a lot of worn screw holes, just not in wood cameras" Denney

Plugging the holes in the wood with hardwood will be as strong or stronger than the original. The stripped screws are most likely the result of removing, replacing, and overtightening the original screws - perhaps in an effort to make the slots line up.

[BrianShaw]

Plugging the holes in the wood with hardwood will be as strong or stronger than the original. The stripped screws are most likely the result of removing, replacing, and overtightening the original screws - perhaps in an effort to make the slots line up.

Stronger. Ask any woodworker or antique repairer or pipe organ builder/restorer. This is the proper way. It puts the thread into end-grain rather than side-grain. It is so proper that when pressure and vacuum tight wood connections are used, that is the repair technique. Shoving toothpicks in the hold is not.

[Sevo]

No, he was talking about gluing in the insert, which is a very good idea.

One of these: http://de.wikipedia.org/wiki/Rampamuffe I assume?

Ugliness aside, it would doubtlessly work, but as others pointed out, there are all wood solutions which are just as strong and historically more accurate.

[E. von Hoegh]

Stronger. Ask any woodworker or antique repairer or pipe organ builder/restorer. This is the proper way. It puts the thread into end-grain rather than side-grain. It is so proper that when pressure and vacuum tight wood connections are used, that is the repair technique. Shoving toothpicks in the hold is not.

I should also add that hardware store/bigbox "hardwood" dowels are not suitable for this work. You need to use something like maple to peg the holes, not crap-grade birch.

[Sevo]

I should also add that hardware store/bigbox "hardwood" dowels are not suitable for this work. You need to use something like maple to peg the holes, not crap-grade birch.

Crap grade birch would not be that bad, if it were just that - what disqualifies the common ready made wood dowels is that they are compressed wood, supposed to expand when wetted with glue. A desirable property when pegging wood surrogates or plywood, but likely to cause solid wood to crack.

[BrianShaw]

E... I reserve my stock of maple and hickory dowel for ramrods, and successfully use the birch dowels for repair of torne screwholes in pneumatic devices. I did not know that any dowels are engineered (I think I knew that some of the pre-made pegs and bisquits were, but never use them) but it has been quite a while since I've bought any. I bought a whole bunch of dowel material many years ago and I'm only using it one inch at a time.

[E. von Hoegh]

E... I reserve my stock of maple and hickory dowel for ramrods, and successfully use the birch dowels for repair of torne screwholes in pneumatic devices. I did not know that any dowels are engineered (I think I knew that some of the pre-made pegs and bisquits were, but never use them) but it has been quite a while since I've bought any. I bought a whole bunch of dowel material many years ago and I'm only using it one inch at a time.

Good dowels are available, and birch can be hard. But what I see in the big volume stores is crap and just not suitable for much. I've just whittled pegs (and rounded them by chucking in a drill and sanding) when I need to repair a hole.

I'm somewhat ashamed to admit that I use fiberglass loading rods in the field, at the range I use a 1/4" stainless steel T-handled rod with a muzzle guide.

[BrianShaw]

... 1/4" stainless steel T-handled rod with a muzzle guide.

Yes, got one too. I never liked it very much. Don't know why though. It is a nice piece of hardware and the concept makes perfect sense.

[E. von Hoegh]

Yes, got one too. I never liked it very much. Don't know why though. It is a nice piece of hardware and the concept makes perfect sense.

At one time I was target shooting and seating bullets with the butt of the gun on a bathroom scale, the T handle was just the thing. I made it out of a 303SS round and stuff from the scrap barrels; I also made followers which conform to the bullet or round ball.

[fecaleagle]

It seems to me that doweling or filling wood will be less strong than the original screws, which, at least over the long run, were obviously not strong enough. If you drill and screw into an epoxy plug, be sure to use exactly the correct pilot drill--epoxy has little tensile strength and can split. Gluing in a dowel and retapping is good preservationist practice, but do you want to use the camera or preserve it?

A question for those in favor of using a plug/dowel over replacing with machine screws... When I attempted to do this previously on the Speed Graphic, I drilled out the holes to size, epoxied in birch dowels from a wood supplier (not from a big-box hardware store), allowed them to dry, sanded them flush, and then attempted to screw the shutter plate back in using replacement screws of the same size, but they did not hold. The reasons why this did not work are not exactly clear to me, but I suspect it was 1) the dowel plugs were not large enough - I used 1/8" dowels because the screws were so small, and I didn't want the work to be visible/to punch a hole in the leatherette on the body of the Speed Graphic, 2) the birch was too soft at that size, and/or 3) the screws were just too small - the originals, IIRC, were size #0, brass wood screws. Any thoughts?

Historical accuracy is much less important to me than functionality. Given this, is the consensus still that the better approach is to epoxy in hardwood dowels and use the original/replacement screws? I will certainly be using bigger dowels, and these screws are already closer to a size #2 than they were with the Speed Graphic, but I was thinking that machine screws were something I'd be less likely to mess up, and the risk of over-tightening and stripping (the hole) is pretty much eliminated with this approach. Basically, I won't have to hold my breath every time I take a screw out or put it back in.

Thanks for all the input. I really appreciate it.
William

[E. von Hoegh]

A question for those in favor of using a plug/dowel over replacing with machine screws... When I attempted to do this previously on the Speed Graphic, I drilled out the holes to size, epoxied in birch dowels from a wood supplier (not from a big-box hardware store), allowed them to dry, sanded them flush, and then attempted to screw the shutter plate back in using replacement screws of the same size, but they did not hold. The reasons why this did not work are not exactly clear to me, but I suspect it was 1) the dowel plugs were not large enough - I used 1/8" dowels because the screws were so small, and I didn't want the work to be visible/punch a hole in the leatherette on the body of the Speed Graphic, 2) the birch was too soft at that size, and/or 3) the screws were just too small - the originals, IIRC, were size #0, brass wood screws. Any thoughts?

Historical accuracy is much less important to me than functionality. Given this, is the consensus still that the better approach is to epoxy in hardwood dowels and use the original/replacement screws? I will certainly be using bigger dowels, and these screws are already closer to a size #2 than they were with the Speed Graphic, but I was thinking that machine screws were something I'd be less likely to mess up, and the risk of over-tightening and stripping (the hole) is pretty much eliminated with this approach.

Thanks for all the input. I really appreciate it.
William

Dowels were too small or too soft, or both. Did you pilot drill the holes too big? You'd use about a .040" drill for #0 screws IIRC.

[BrianShaw]

... but I was thinking that machine screws were something I'd be less likely to mess up, and the risk of over-tightening and stripping (the hole) is pretty much eliminated with this approach. Basically, I won't have to hold my breath every time I take a screw out or put it back in.

R&R of a wood screw should be a fairly rare event. If you are planning to R&R often, then maybe the non-traditional approach would be best. I assumed (I seem to be doing too much of that too often lately) that you were planning on mounting a back and leaving it there.

[fecaleagle]

I'll check my drill bits when I get home, but the pilot hole size is a likely possibility. Although I purchased replacements from bolt-depot and I believe the recommended pilot hole sizes came with my order. I'm usually good at reading/following explicit instructions. Anyway, the bottom line is that if I move up to a 1/4" hardwood dowel (harder than birch) with a #2 size screw, and the pilot holes are drilled to the correct specification, I'm likely to be okay.

If I go with the machine screws, I'll have more peace of mind about the durability of the work, but I will need to use a weak-medium threadlocker, and I will have to combat the occasional tinge of guilt that I have modified a piece of history with a historically-inaccurate repair approach.

[BrianShaw]

... I will have to combat the occasional tinge of guilt that I have modified a piece of history with a historically-inaccurate repair approach.

I understand entirely. "Get over it." That's what I have to remind myself any time I use a non-reversable, non-traditional restoration/repair solution that works well. :)

[fecaleagle]

R&R of a wood screw should be a fairly rare event. If you are planning to R&R often, then maybe the non-traditional approach would be best. I assumed (I seem to be doing too much of that too often lately) that you were planning on mounting a back and leaving it there.

Thanks to everybody for all the advice. I'll most likely dowel the loose screws that I can't conceive of needing to "R&R" more than once every 5 years, but I'll replace the ones that hold the back/ground glass on with machined inserts.

Best,
William

[E. von Hoegh]

Hopefully you won't be using allen or phillips screws.....

[Drew Wiley]

There are several ways of doing it. If you use inserts go to someplace like McMaster that
has a serious selection, including epoxy-in types which won't split the wood. As far as dowels are concerned, lots of the hardware store product is now cheapo ramin wood, with poor dimensional stability. I like to use high-quality plug cutters on a drill press instead, with matched brad-point bits. Ordinary drill bits won't leave very clean holes. But any cabinet shop worth its rent knows how to do this kind of thing.

[cowanw]

You could split the difference and use dowel plugs and then tap them for machine screws. Stronger than wood screws according to Lee Valley Tools. I just did this on lens boards because I couldn't bear the weenie screws usually used.

[Roger Thoms]

Has anyone tried this tapered reamers from Lee Valley? Looks like it might work well for repair stripped out screw holes.

http://www.leevalley.com/US/wood/page.aspx?p=32280&cat=1,180,42240,53317

Roger

[rdenney]

You could split the difference and use dowel plugs and then tap them for machine screws. Stronger than wood screws according to Lee Valley Tools. I just did this on lens boards because I couldn't bear the weenie screws usually used.

And if you impregnate the wood with epoxy (such as the rot protector stuff like Git-Rot) and then drill and tap it for (course-threaded) machine screws, it will work even better. This is a reasonable solution for rarely removed screws.

The screws themselves will tap threads in the hole if it's just the right size. And it does hold better than very small tapered wood screws. Use the longest screws you can.

Rick "who has done this in several instances with good results" Denney

[E. von Hoegh]

Machine screws in wood? Ludicrous.
Do it correctly with wood screws, drill the correct size pilot hole, don't overtighten them, and everything will be just fine.

[cowanw]

This may be of interest.
https://umdrive.memphis.edu/jthieme/www/Using%20Machine%20Screws%20in%20Wood.pdf


Machine screws in wood? Ludicrous.
Do it correctly with wood screws, drill the correct size pilot hole, don't overtighten them, and everything will be just fine.

[E. von Hoegh]

This may be of interest.
https://umdrive.memphis.edu/jthieme/www/Using%20Machine%20Screws%20in%20Wood.pdf

A test by the makers of a product isn't going to convince me of anything.
A properly applied woodscrew works just fine. They've been holding my Deardorff together for 62 years, even though they all were removed and replaced at least once when I restored it.

[Drew Wiley]

The term "wood screw" is basically meaningless, esp if, like me, you are at the moment sitting about thirty feet from a room with about two million dollars worth of hundreds of different types of the damn things. Like I stated earlier, the average Joe should just peruse
something like the McMaster Carr site to merely get an introduction to the variety of items
applicable to such projects - and their selection is by no means exhaustive. I've got all kinds of personal camera projects on hold using everything from structural graphite to
phenolic/fiberglass resin to selected hardwoods, epoxy-treated. Don't know how many of
these ventures I'll actually complete. At the moment I'm more interested in taking my refurbished Sinar Norma for a walk this weekend.

[rdenney]

Machine screws in wood? Ludicrous.

No offense, but this sounds like guessing to me. Let's speak from actual experience of repairing damaged holes (which was the subject of this thread).

The point (so to speak) of wood screws is to prevent the need for cutting threads in the wood. The sharp, narrow threads and untapered shank (at least past the gimlet point, which was a later addition) were intended to do the thread cutting. The unthreaded shoulder is a locking device to wedge into the freshly cut threads near the head. Gimlet points were added (after half a century) to make them easier to drive into a pilot hole. The threads are coarse because of the requirements to drive into untapped material, to work in soft material, and to facilitate hand-cutting (wood screws were originally hand-cut).

The problem with short wood screws, as often used in cameras, is that the gimlet point consumes the whole threaded portion, which means they loosen easily. And because each cut thread in the wood is smaller than the next, any wear affects all the threads on the screw.

A machine screw is a later invention. It has triangular threads with pointed roots, which will tap but not as easily in soft wood. The straight threads even in short length improves the overall holding power. In longer screws, the threaded section is quite strong, as Bill's linked article indicates.

So, traditional wood screws are a convenience to the maker, both of the screw (in the earliest days--machine screws have been easier to make for about 150 years), and of the wooden thing being constructed. Tapping holes for machine screws requires appropriate wood choices and grain configurations, but I've done it a lot and it works.

Rick "thinking the wood-screw concept is more tradition than design" Denney

[E. von Hoegh]

No offense, but this sounds like guessing to me. Let's speak from actual experience of repairing damaged holes (which was the subject of this thread).

The point (so to speak) of wood screws is to prevent the need for cutting threads in the wood. The sharp, narrow threads and untapered shank (at least past the gimlet point, which was a later addition) were intended to do the thread cutting. The unthreaded shoulder is a locking device to wedge into the freshly cut threads near the head. Gimlet points were added (after half a century) to make them easier to drive into a pilot hole. The threads are coarse because of the requirements to drive into untapped material, to work in soft material, and to facilitate hand-cutting (wood screws were originally hand-cut).

The problem with short wood screws, as often used in cameras, is that the gimlet point consumes the whole threaded portion, which means they loosen easily. And because each cut thread in the wood is smaller than the next, any wear affects all the threads on the screw.

A machine screw is a later invention. It has triangular threads with pointed roots, which will tap but not as easily in soft wood. The straight threads even in short length improves the overall holding power. In longer screws, the threaded section is quite strong, as Bill's linked article indicates.

So, traditional wood screws are a convenience to the maker, both of the screw (in the earliest days--machine screws have been easier to make for about 150 years), and of the wooden thing being constructed. Tapping holes for machine screws requires appropriate wood choices and grain configurations, but I've done it a lot and it works.

Rick "thinking the wood-screw concept is more tradition than design" Denney

So when I restored the box of my 1825~ Parkinson & Frodsham chronometer I should have used machine screws instead of pegging the bad holes and hand-cutting replacement screws?

Sorry, I'll leave the butchery to someone else and continue to repair my old things with the correct methods.
When I made a set of speakers, I used steel machine screw inserts, epoxied, for the screws which hold the drivers. Horses for courses.

[Drew Wiley]

If I had to replace a bunch of screws on an old mahog camera and wanted to retain the
classic look, I'd opt for silicon bronze rather than brass - way way stronger and far more
corrosion resistant. You find this kind of thing at marine stores.

[rdenney]

So when I restored the box of my 1825~ Parkinson & Frodsham chronometer I should have used machine screws instead of pegging the bad holes and hand-cutting replacement screws?

Sorry, I'll leave the butchery to someone else and continue to repair my old things with the correct methods.
When I made a set of speakers, I used steel machine screw inserts, epoxied, for the screws which hold the drivers. Horses for courses.

In my first message on this topic, I made the distinction between preservation and repair for actual use. Not everyone putting an old thing back together cares about preserving it in its original state. But if one does care about that, he knows what to do.

Rick "who just wants cameras to work" Denney

[E. von Hoegh]

In my first message on this topic, I made the distinction between preservation and repair for actual use. Not everyone putting an old thing back together cares about preserving it in its original state. But if one does care about that, he knows what to do.

Rick "who just wants cameras to work" Denney

I've found that, when dealing with any kind of quality item, the original methods of fastening and reataining are more than adequate and any problems are the result of neglect or abuse. @#!*% few people even know what a proper screwdriver is, let alone how to use one.

E. "who wants his stuff to work too but won't stoop to bad craftsmanship or kluges for any reason" von Hoegh.

[normanv]

The problem with using dowels to plug the hole is that the screw goes into end grain which is not a good idea as the fibres are cut by the screw thead. I would go the way of filling the hole with a flexible wood filler and then drilling a pilot hole for the screw.

[rdenney]

I've found that, when dealing with any kind of quality item, the original methods of fastening and reataining are more than adequate and any problems are the result of neglect or abuse. @#!*% few people even know what a proper screwdriver is, let alone how to use one.

E. "who wants his stuff to work too but won't stoop to bad craftsmanship or kluges for any reason" von Hoegh.

Not always possible if there have been poor craftsman in the item's past.

But it's not a kluge to replace something a manufacturer did for his assembly convenience and replace it with something actually more difficult to install, but more durable in the long run.

A matchstick in a worn hold is a kluge. Filling the hole with Elmer's Glue, driving the screw, and letting it dry is a kluge. Replacing a worn-out hole with a properly installed insert is not a kluge. Using a machine screw instead of a wood screw in a brand new hole is not a kluge if the wood is appropriate.

For example, on clocks it's customary, and not at all a kluge, to drill out worn pinholes and press in bronze bushings to restore the hole. The alternative would be to make a new plate, or to fill the plate with brazing material, re-harden it, and then redrill it. Which is better? If I'm trying to make it look original, I might do the latter. But the former is a completely proper repair that will last longer than the original design.

Rick "agreeing that most people don't know how to use the right type and size of screwdriver" Denney

[E. von Hoegh]

Not always possible if there have been poor craftsman in the item's past.

.......

For example, on clocks it's customary, and not at all a kluge, to drill out worn pinholes and press in bronze bushings to restore the hole. The alternative would be to make a new plate, or to fill the plate with brazing material, re-harden it, and then redrill it. Which is better? If I'm trying to make it look original, I might do the latter. But the former is a completely proper repair that will last longer than the original design.

Rick "agreeing that most people don't know how to use the right type and size of screwdriver" Denney

Brazing the plate of an antque clock is inexcuseable and unforgiveable butchery.

Pressed bronze bushings are only appropriate on clocks which used these originally. Bronze bushings in anything else is a kluge. Some quality English fusee movements had gunmetal (type of bronze) bushings for the fusee arbor.
The proper method of rebushing a quality antique clock is to broach out the pivot hole, chamfer the small side of the broached hole, and rivet in a piece of prepared hard bushing wire. Broach the pivot hole to the proper location, and finish the pivot hole with a polished broach, broaching from each side to leave a pyramidal annulus in the middle of the hole. Lastly recut and polish the oil sink. A pivot hole prepared in this manner will last almost indefinitely if kept clean and lubricated.

E. "you really shouldn't try to tell me about watch and clock restoration" von Hoegh.

[David Beal]

One more tip, if you're going to put brass wood screws into wood plugs (and plugs are a good idea): when the plug is in place, drill a small pilot hole and insert a steel wood screw of the same size as the brass one you want. Tighten it down so that the steel will cut a thread. If you try putting a brass wood screw into an unthreaded pilot hole you run the risk of snapping it; and it's no fun to try to remove one of those thing!

Good luck with the project.

/s/ David

[BrianShaw]

I put a very small tiny bit of wax on the threads too.

[fecaleagle]

Thanks for all the excellent advice, guys. I will follow-up and let you know how things turn out.

[Drew Wiley]

Typical furniture woodpatch materials are fairly worthless outdoors if your varnish fails. Don't hold screws well either. Polyester fillers resembling Bondo are also inadequate - brittle
and won't hold to wood fiber particularly well. If you do go a synthetic filler route, it should
be a two-part epoxy specifically blended for wood use. If you use glue-in inserts, and appropriate marine epoxy glue should be used, or in a pinch, something like Gorilla polyur.
glue. For you purists who want a Dorf to look like a Dorf, I guess it's gonna be traditional
slotted brass screws - but make sure all the slots line up in the same orientation, just in
case a certified Dorf inspector shows up in the neigborhood!