Wooden Lens board Repair - Best Practices

[Peter De Smidt]

I have a original 9x9" lens board that has a crack through the wood. See:





It's a pretty thin crack. What's the best way to repair this? Filling it with a wood epoxy using a putty knife to work into the crack, or....?

[Louis Pacilla]

I simply add a couple layers of black gaffers tape over the crack and not so large as to cause the board to be a *weak link. However IF it's a split that can be pushed back onto square then glued & clamped or in other words when it's not a crack but a split at one of the two tongue & grove seams on the board.

BTW- Peter your Ansco/Agfa #5 takes the same lens board as your #7 Century 9"x9".

* This "weak link" is actually not a real problem though as the flange w/ the several screws around the perimeter will strengthen the crack on the lens board. So most times even with the crack the lens board will be plenty strong enough to solidly hold most lenses just fine is you cover the crack on the back side with black gaffers tape and you can get to shooting

[Peter De Smidt]

Thanks Louis. I tried an original Century board yesterday, and it almost fit. I'll try more carefully today.

[Mark Sawyer]

I'd work a bit of carpenter's glue into the front and back with my finger, clamp and wipe off the excess with a damp rag.

[mdarnton]

Cracks like this develop because of tight fitting lens mount rings, and the cross-grain pieces at the edge of the board, such as I can see on your board. When the wood shrinks over time, the ring and end strips hold it in the pre-shrunk dimensions, and something has to give. You probably won't be able to get it reliably closed so that it will stay closed, so you need to fill the crack with something that doesn't transmit light. My choice would be black epoxy (not a clear type!) or bondo. A lot of the neater things you could try, including stuffing it with glue, probably aren't going to be light tight if the crack goes all the way through. If I were doing a semi-fancy thing here, I'd mix wood shavings and glue in a very dry (minimal glue) mix and pack them in tightly, with the possibility that this might not turn out to be light tight. Shave the mess level after it dries, and repaint the board (it looks black?) But I'd probably do bondo, myself.

[Louis Pacilla]

Usually it's the light trap being a bit different that makes one 9"x9" board not fitting another camera and with a bit of filling it may be easily be made to fit both cameras. I have NEVER had a light leak from the lens board light trap failure while using any of my studio cameras but that may be more a factor of the low light level hitting my camera when shooting indoors w/ the controlled lighting.

I have at least 40+ 9"x9" lens boards and some fit both some fit one of my century's and not the other Century's but will fit my Ansco/Agfa camera so it's not always across the board. No pun intended. Then theres the 8a w/ the 10"x10" lens boards. I have two Ilexpo shutters though one 9"x9" and one 10"x10" that take 6x6 boards so many of my lenses that fit that board size are mounted on them so I can use them on any of my studio cameras by moving the 9x9 Ilexpo around.The 10x10 Ilexpo stays parked most times on the 11x14.

[Peter De Smidt]

I used JB Weld wood epoxy, using a clean, flexible putty knife to work the epoxy into the crack. After that dried, I pained the back of the crack with matte black artist's acrylic, and I also painted the inside cut edge of the hole. That edge is the only non-sealed one on the board, and differential drying might've exacerbated the crack. Hopefully, the repair will hold up.

[Jac@stafford.net]

Peter, in my modest experience wood putty shrinks. Not good. A good animal glue injected and properly clamped over-night is good. My last resort is that awful scoundrel Gorilla Glue because properly applied to wet surfaces it blooms to each surface, which requires us to refinish the mess it makes.

But you probably know all that.

[LabRat]

Peter, in my modest experience wood putty shrinks. Not good. A good animal glue injected and properly clamped over-night is good. My last resort is that awful scoundrel Gorilla Glue because properly applied to wet surfaces it blooms to each surface, which requires us to refinish the mess it makes.

But you probably know all that.

FYI;

I'd stay away from Gorilla Goo, as it is VERY hard to control in use, hard to remove where it transfers to (easily) during use, can foam up too much out of contact areas, and joint is slightly spongy when set...

I'd run some superglue into it and clamp...

Steve K

[pgk]

Many years ago my father used to repair woodwind instruments most of which were then made of wood (ebony sometimes or similar timbers). They too cracked. They had to be filled and to do so in a wood subject to both humidity (from breath) and temperature changes meant that simply filling them would not work as the filler would not expand and contract with the wood. To make a repair he used to use a very fine drill to cut holes through the crack at 90 degrees to it and then wind fine steel studding (threaded rod) into the hole. This provided a strengthening and stabilising brace and filler could then pressed into the crack, as it could no longer move.

This might be a viable on cracks in a lens board if they could be drilled and if the crack looks likely to increase or even split the board perhaps? That said I think that he used a fine drill and then a rod with a hardened cutting end which he had made himself to increase the length of the hole if needed. It wasn't an easy job but was a good solution for a decent instrument. Brass studding might be better on a lens board and could be made from brass rod using an appropriate die maybe?