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Jani Heikkinen
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 24, 2005 - 11:29 pm: | 
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Hi!
I just got myself a rather rare old wooden folding platecamera which I have been looking for quite a long time. Although it has lots of things to repair and restore, one problem is the most urgent. The wooden bottom part where the folding metal frontcover is attached to, has bent about 5 mm. There is a spring in the middle of the joint between the cover and the bottom part, which keeps the cover closed and provides the movement to close the cover. For some reason the wooden bottom has bent starting from the place where the spring is attached to the wooden body. The wood is some kind of dark and very dry wood, probably ebony but I'not sure. How should I try to bend this wood back? The wooden bottompiece is about max. 10 mm thick and everywhere else it is not bent, just in the front where the spring is. Is there something to treat the old wood with so I could slowly bend it without breaking it? Also probably the only solution to prevent the spring from bending it back is to replace the spring with a smaller one. |
P Laskey
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 25, 2005 - 02:24 am: |
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It sounds as though the wooden piece needs replacing altogether, when wood warps like this it's impossible to get it back into shape as far as I know. Either that or the warped material could be cut out and a replacement section of wood glued in.
P Laskey |
Jani Heikkinen
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 25, 2005 - 03:14 am: |
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I'm afraid that replacing the part with a new one is impossible. What if I'd just soak the part wet and then put it into a press and let it dry again. I have done this with more common wood types, but I wonder if wetting this kind of old and very dry hardwood just makes the situation worse. |
Glenn Middleto
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Votes: 0 (Vote!) | | Posted on Friday, March 25, 2005 - 08:10 am: |
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Build yourself a steamer or use a kitchen veg steamer.Get the wood really hot and pliable,then use bookpress or woodworkers vice. Leave under pressure untill completely dry and stablised to humidity of your dwelling. Sometimes you may have to conjure up a 'jig' to put a bit of over correction into the piece whilst it is drying.You only find this out after the first attempt does not fully work.Then refinish the wood with linseed oil or varnish-the refinishing is important if original warp was moisture induced.Another trick that I have used to get an old studio camera to work,not a rare piece I wanted a user-the warp would not fully go using above.I machined very fine slits,using slitting saw in lathe,in the convex side of warp to a depth of 3/4 of wooden piece. steamed piece and then worked waterproof adhesive into slits and pressed part.Outcome was a straight usable sidepiece,which some 3years down the line is still looking good.This may seem drastic,but I like the equipment to look right and be useable and in all honesty you have to look very hard to see see what I did.Also most modern adhesives used properly produce a bond stronger than the wood. |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 25, 2005 - 10:59 am: |
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I was going to suggest steam too - that's how things like bentwood rockers and formed plywood chairs are done. i've never done it myself though, so don't trust me for specifics. it seems that a fixture where you could gradually apply pressure as the wood softened might be helpful, and it seems like it would be good to design it so that the moisture could escape from the wood without having to release the clamping force first.
: ) = |
Jani Heikkinen
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 25, 2005 - 09:27 pm: |
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What do you think, would a steam iron work? With it I could also apply the pressure to the wood... and it would warm up the wood fibers which is needed for bending it. |
Robert
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 25, 2005 - 11:29 pm: |
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Jani....
Steam Irons are for clothing !!.., not made for "Wood Working".., at least this type of operation anyway !!....
Glen is right in his "How To" !!.., follow his instructions and you will see very good results !!...
I've done so, years ago with my field camera and it worked great !!.., but don't expect immediate results after your first attempt, you may have to do the steaming more then once !!....
Take your time and patience will pay off !!....
Good Luck !!....
R...... |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 26, 2005 - 08:43 am: |
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Thanks Robert for that +ve 2nd opinion.I also like looking at old boat building techniques-some of the timber they steamed was beyond belief!My steamer consists of an old pressure cooker,length of rubber hose and various tin boxes (old biscuit tins )with inlet and outlet in their bases.The hose is fixed to the spigot on the cooker lid that the weighted pressure device normally sits on,just use hose clip to retain.Hose just pushes into a big enough hole in boxes.You only need a small hole to act as drain,a bit of +ve pressure is a good thing.I use this to remove dings from wooden items,that is why I have knocked this up.If part fits in veg steamer,get one at boot sale.The repair of camera is important thing in this instance.Glenn |
Charles Fallis
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 26, 2005 - 07:38 pm: |
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Ebony is an EXTREMELY brittle wood, so bending it may very well break it. One way to tell if it is ebony is that as ebony dries and ages, then unless it is kept oiled or waxed it quite often develops small surface fissures and cracks. You certainly will not be able to straighten by steaming the surface with a steam iron, but will need positive atmospheric pressure to force the steam into the wood. Musical instrument makers (who sometimes work with ebony) form their wooden instruments under quite a lot of steam pressure. The pressure cooker and vegetable steamer ideas seem like the ones most likely to work. |
Jani Heikkinen
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 28, 2005 - 04:29 am: |
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After a closer inspection some of the parts are ebony, but the main body parts seem to be teak(according to my not so good knowledge of woodtypes). Anyway, it at least looks like the pieces of teak I already have. What is your experience with old and dry teak? Or are there other woods used in cameras that resemble teak? It has about the same colour and same kind of random grooves as a pattern. |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 28, 2005 - 08:31 am: |
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Hi,It may be teak, but how old is camera because teak is very difficult to glue with animal based hot glues.these were the staple adhesives untill the casin types etc of recent history.I would
hazard a quess that it is a 'rosewood'derivative.
I do not know the latin names, but some of the family exhibit that open grain pattern.The 'glueability' of the wood used in camera bodies was important because it was just good basic cabinet making methods that were used.All woods will steam bend,in fact unless wood is 'green' steam is the only way to work large sections.Much green timber was used in boat building before advent of wrought iron/steel.I can sense that you are worried,so do an experiment with that piece of teak and any other pieces of hard wood you can lay hands on. Make rough replicas,size wise,of your warped item.Dry them out at 105 deg C for at least 48hrs,Let cool and then steam for say 1 hr.Then support each end on blocks and using G cramp and piece of halfround block bend test piece down onto table,let dry.depending on block height,you can get quite a bend.This will give you a feel for method-Just try same with DRY wood!I gained my experience from building model boats and studying old boatbuilding methods.I really think a bit of hands on experimentation will help you in this.One other very important thing;DO NOT STEAM THE ITEM IN A PRESSURE COOKER.You need real knowledge of how the particular wood behaves at elevated temperatures before doing this.Yes it can dramatically reduce steam time,but leave longer than required and wood starts to degrade and be digested.Sorry I cannot be more helpful,it's not like you have a scraper to play around with.Glenn |
Winfried
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 28, 2005 - 12:08 pm: |
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I am everything but familiar with wooden cameras, but I think you should ask a cabinet maker or someone restoring old furniture. Actually, many wooden cameras in Germany were made by 'Kameratischler' (i.e. cabinet makers making cameras). These guys should know more about restoring wooden things than most of us do.
Maybe even a repair shop for wooden musical instruments can help you. I recently saw a feature on TV (partially) on old wooden instruments. Someone brought in a semi-broken old violin where the cover had separated from the frame, and the specialists told him it should be no problem for a skilled repairman to fix this. |
Jani Heikkinen
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 28, 2005 - 08:25 pm: |
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Thanks everybody! And Thanks Glenn, I will try your way of testing first on other pieces of wood, as you are right I don't know how wood will bend with steam so I need to experiment first.
Yesterday I was removing the leather from around the wooden piece by wetting the leather and the wood. I got the leather off easily, but when the wooden part was damp, it had gone back to it's correct position and was no longer bent. After I let it dry out over night, it had bent back and was no longer straight. |
Jani Heikkinen
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 29, 2005 - 06:05 am: |
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Today I tried steambending on old pieces of wood. I had a broken wooden plateholder that was made of the same wood as the camera bottom. From the plateholder I got a nice piece of as old and dry wood as in the camera and the thickness was the same. First according to some information I got elsewhere, I soaked the testpiece of wood thoroughly, then used a steam-iron with full temperature and full steam pressure along with clamps etc. It took some time but I succesfully bent the piece quite a lot. After drying the piece of wood, it came back a bit, but no more then I had anticipated it would. Later I will write here how it worked with the camera. |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 29, 2005 - 06:26 am: |
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Jani,when piece was damp were both sides wet, or just one? As you know the wet side will expand, so wetting concave side will straighten a bent piece until it dries.I am trying to get some idea of how much you will have to over-bend piece to give you straight, dry item.If steaming does not fully work is the formation of partial depth fine slits and glue an option, as I mentioned in first post. This can relieve stresses in the wood. |
Jani Heikkinen
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 29, 2005 - 06:30 am: |
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Yes, it was damp only on the concave side. Unfortunately the fine slits and glue is not an option. |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 29, 2005 - 06:35 am: |
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Jani,ignore my last post, your 06.05 was rolling down wires as I wrote.Glad you are getting feel,have a great success. |
janierik
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 02, 2005 - 10:52 pm: |
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Hi everyone!
I moistened the wooden bottom part after removing the leather. Then I warmed up the wood with a steamiron and bent it. I also added a few clamps to help with bending while warming the wood. I did bend it a bit over the straight position, but as I guessed it bent back a bit when drying, so that it was straight afterwards.
I also removed one of the two springs used in the camera door and the functionality of the door was just as good with one spring as it was with two. Still however the spring bent the wood a bit but this time when opening the camera and removing the tension, the wood went back straight. Due to the door, the wooden bottom cannot be bent so that it would remain overbent and that way compensate the bending force of the spring.
Also I have found that this problem occurs also on other cameras of this model, so it could be a design flaw.
It seems that unlike many others, this camera must be kept open as much as possible to remove the strain on the wooden bottom.
Again, thank you for all your help. |
