Mahogany Plate Holder crack repairs . . . ??

I have acquired a new family member who came with 5 book-style Mahogany plate holders (12"x10"). Most of the dark-sides have a small crack or two that must be filled. Several have large cracks. I was curious what others have used, that which works well. I prefer to fill the cracks with "something" that won't disturb the shellac on the front of the holder. And whatever material is used as the filler, I can easily cover with aged shellac using a fine paint brush. I know that some wood fillers contain an epoxy the gets all over everything. Once the epoxy dries . . . it's all over but the crying. Many thanks in advance.

I'm a bit confused.. Are the slides really slides– do they have to slide in and out of a slot in the holder? If so, patching cracks is going to be quite difficult. The thin wood is compromised by cracks and any patch would likely add thickness and very little strength across the grain of the wood. Having said that, I will add two things about patching hardwood. Free advice and worth every penny.

The first is that shellac cannot be used "aged." Old shellac will never dry; it has a definite shelf life. It is better to gently remove all the shellac on the surface with denatured alcohol and then reapply (orange or clear) shellac over the entire surface after patching. Shellac has not changed much in terms of composition or look over the decades and it is one of the easier finishes to match.

The second point is just a suggestion. Many of the professional cabinet-makers I know use mahogany sawdust mixed in with wood glue instead of commercial wood filler. It helps to have very fine sawdust from the same type of mahogany that you are patching (such as dust from a band saw). It also helps to have scrap from the same boards from which to make the sawdust, since there are many varieties of wood known as "mahogany" and the color of each is, if not unique, at least quite distinctive.

Good luck!

The sawdust and glue method works very well and I have used that method quite a lot.
The "traditional" glue would be white carpenter's glue, but cyanoacrylate glues (AKA "Super glue") work well for this also. Both are completely reversible.

You may need to mix some colorant into the mix if you want to match the color. Old mahogany will probably be darker than most of what's currently available.

Also, if you go for the super glue method, get some water-thin type from a hobby shop (the typical product has thickeners), and then you would pack the sawdust into the crack then apply the glue in drops. The sawdust will wick the glue. You may also need to spray it with a setting accelerator to finish things off.

BTW, there are several grades and colors of shellac, from deep amber to almost clear. Woodcraft (www.woodcraft.com) has some good videos that go into the details of the various shellac grades and types.

another vote for sawdust and carpenter's glue ...
that said ... a friend who is a sculptor, woodcarver, boatmaker, cabinetmaker
and all around wood-smith stopped using sawdust a few years ago
and uses gorilla glue nowadays ...
if you want to go totally analog you can make your own shellac
but it might take you a while to get the bugs
http://en.wikipedia.org/wiki/Shellac

Oh, I have plenty of experience with shellac. I have been reconstituting what I have for many years. In fact, I used it just the other day to french polish some more lens boards. It started life as clear shellac about ten years ago, and today it's a dark mahogany color. Still dries hard. That's why I called it aged shellac. The shellac is really not at issue here. But a filler that will look appropriate and stay put would be my primary concern.

The slide must slide over the seal on the camera body itself, and the seal inside the holder. So, the surface, both inside and outside, must be somewhat smooth. Electrical tape is an option I have used. But it is only temporary. It can eventually give way, and become detached.

Here are some pictures of one holder . . .

View attachment 95184 View attachment 95185

The very best way to deal with it would be to completely dis-assemble the holder glue the cracked panel and re-assemble. In theory, those panels should be ever so slightly loose in the frame so that they can expand and contract a little. Most likely, that movement (or lack of it) is what has caused the crack. Disassembly could be a daunting project though, it would probably be difficult to get it apart without causing more damage.

Home brew wood putty as noted above, would probably work ok, or black black silicone would work well too, but maybe not in keeping with the old-tech-ness.

Dis-assembling the panel is not really an option. And reason being, I could easily cause more problems with the holder than just the crack that is currently present. Plus, I much prefer not making alterations to the camera and holders when possible, as to retain it's natural and aged beauty (worn-out look). BS at it's finest.

I suspect that that particular inset panel was not thoroughly dried when the holder was originally assembled. Over the hundred years or so, the moisture and oils originally present in the panel simply dried out, and the panel contracted accordingly. That's my hypothesis. Nonetheless the dark-side functions properly, and it is flat.