This is the result of having a longcase clock standing on heated floor tiles. The owners moved to a new house with floor heating and one day the front of the longcase clock trunk split in a nasty way. You can see the wood behind the veneer has bended by the dry air and split. Its from a grand 18th century mahogany longcase clock made in Liverpool circa 1775 with beautifull bookmatched mahogany veneer. Only a few pieces of veneer are missing, but how do I get the planks flat again I really don't know. I will post a picture of the whole clock tomorrow.
I'm not a specialist in case repairs and the experts will surely chime in. it might be a good idea to move the post to the case restoration section. My feeling is that the piece needs to rest for quite some time in a climate controlled environment with maybe 50% relative humidity in order to straighten by itself. Then the veneer repairs can be made. The bigger problem is how to prevent this from happening again? Is there an area in the house where the floor under the clock is not heated. I suspect that the dry, warm air was trapped inside the case making things worse. Uhralt
Hmm, you need our magician in Oxford, but I'm not entirely sure that you can. The veneer can be lifted and put on new boards. 17th century cases usually have a bow in the sides because the veneer is on one side which limits the drying on one side while the unfinished inside shrinks. I believe the same happens with painted wooden dials. We could send it to him.
Yes indeed a magician, but I really want to do it myselve with some good advise. Would he be willing to give some?
You could try asking JC Pitre (he contributes quite often to this website and his webname is SOOTH). He is a man with very impressive skills as a cabinet maker and with much experience in veneering. JTD
I've attempted repairs of this type, with very little success. I've tried getting the panel fairly wet and clamping flat until it dries, but it generally reverts back to the original warp. I can tell you that the veneer is most likely to have been applied with hide glue. And by applying moderate heat it can be removed quite easily. My thoughts would be to apply the old veneer to a thinner flat one piece panel and then re-attach to the original backing.
Dave, thank you for letting me know! Its good to hear from someone who tryed this allready. You mention "moderate heat" , do you mean by using a hairdryer? And how do you remove the veneer after the hide glue is softened by the heat?
Like Dave T I have not had any really good results from efforts to keep a once warped panel permanently flat. What I have seen used effectively but of questionable integrity is kerfing the backside of the substrate on something like 1/4" spacing, filling the slots with epoxy, clamping the piece with flat metal plates on both sides until the epoxy sets. I like to use a vacuum bag to clamp the plates together as it applies force to the entire piece. Not a museum conservator approach. And certainly not reversible, but it will keep the panel flat for a very long time. A similar destructive approach is to affix the wood parts to an aluminum plate, say 1/4", using epoxy and extensive or vacuum clamping. It will hold the panel flat. I don't recommend either of these approaches but there are no simple or neat solutions. Making a replacement panel of high-density fiberboard may be a better solution, but finding a proper veneer that looks like the original will be tough. I have a similar problem with a water damaged clock right now. I have been thinking about my problem and doing nothing for more than a bit.... Central heat with no humidifier during the winter has destroyed a lot of fine clock cases.
Hide glue will become liguid at around 140-150 degrees. It should soften enough at 120-130 degrees to remove the veneer. Use a steel 1 to 1.5" putty knife with a sharp edge. Heat the blade along with the veneer and slowly push it under the edge of the veneer. Go slow, take your time, and give the hide glue time to soften. Trying to do this quickly will end in the veneer splitting and coming apart. Blow the hair dryer you want to use on a thermometer to see if it will produce the heat you are looking for. Heat guns are not expensive and may be the best investment to make for this project.
You could use a regular electric iron (for ironing clothes). Put a towel on the surface and apply the heat. And a hairdryer would probably also work. As for the veneer, it appears that enough of it is left to re-use and then blend in areas with a close match, or fill it with proper color wax and camouflage it with some black paint or some such.
Thank you all for your advise. Untill now I was advised to solve the problem in two way's. First one is try to get the boards flat again and the other way is removing the veneer and then apply it back on a newly made board. As I am very anxious to remove the veneer, I will first start by trying to straighten the boards and leave the veneer in place. If that will not work, I will then go for the second option to remove the veneer. I will let you know the result either way.
I have not generally had success at removing veneers. I have tried heat, hot air, steam, soaking small pieces in water, careful lifting using wide blades, etc. Hide glue can be very tenacious and usually remains so. I was attempting to salvage some veneers as recently as a couple of weeks ago. My only real successes have been on pieces where the glue has already failed or is well into the process of failing. Hot air and a wide blade seem the best approach but most often the finish on the veneer will fail well before the glue softens even a bit. The finish will bubble and lift and become a problem also, at least it has for me.
Sadly, though I know he could do the work brilliantly, the magician is reluctant to engage in email correspondence about it. I can understand, he works in a converted stone cowshed in rural Oxfordshire with no phone or internet, he just likes to get on with the job. I know he would lift the veneer though, it's what he does.
Nick, thanks for trying. What a wonderfull hobby this is! Never expected to dive into this kind of restoration, see what the result will be.
Clamping of the split front has been done now and its almost 100% flat again. I strenghten the back and now I I started with all the small cracks in front of the panel. I think it will look good after I finished it.
It does look quite a bit better now. I also cleaned the whole case. The timbers that are used on this clock are so thick! Oak inside and nicely figured mahogany veneer. And now I have to start working on the movement
Well, I came in too late to give my two cents, but the repair turned out beautifully. The problem with MANY cases like this is that they're basically paper thin stock, and in this case the extreme drying shrunk and dried the interior. I would have suggested applying water to the interior portions to expand them on the shrunken side. Removing the veneer is another option, but it can be quite difficult. Often you need to submerge the parts in something like a bath tub for extended periods of time until the glue fails.
