metal inlay

[enrique]

Hi Guys,

first time posting, I need advice due to technical challenge.

I am building a dinning table in solid american wallnut, which has an aluminium (3mm) inlay. My polisher and the paint supplier do not want to apply a full finish over the alumin while in place as they are worried about bond and stress fractures due to movement.

Now I have seen this technique being applied by "Knoll" in their office case goods. Any body has any experience they can share or guide me to a resource that can help ??

Finish I am considering is a 10% poly (BC coatings)

many thanks.

[Harry72]

Long as the wood underneath the inlay is solid one piece, not on a joint between two boards and the channel is the correct size it shouldnt crack the finish. I've seen poly cover brass strips on floor boards between rooms and it hasnt cracked even with people walking on it...
The only problem I can see is the channel would need to be very accurate, aluminium and wood are very different so the sanding rates would'nt be the same making it hard to get a level surface? Maybe put the strip in after the finish, just need to allow for the finish's thickness.

[IanW]

The only problem I can see is the channel would need to be very accurate, aluminium and wood are very different so the sanding rates would'nt be the same making it hard to get a level surface? Maybe put the strip in after the finish, just need to allow for the finish's thickness.

While it's true that wood and metal sand differently, in practice it seems to be fine, as long as you use a flat sanding block and are careful. I use quite a lot of brass and wood together, and I usually try to work it so that the wood is a fraction higher than the metal inlay, so that you're sanding the easier part back. But sometimes I'm a bit off, and the brass comes a fraction higher instead, but it doesn't matter too much, brass sands very easily and well, too. Not sure about aluminium - it's so soft, and if your paper is too coarse to start with, you'll drag bits of metal over into the wood, and if the wood is open-grained, they'll lodge there and be a nuisance to get out. (The same sort of thing happens when you put a dark inlay into a very pale background, so it's recommended to use a 'sanding sealer' under these circumstances - probably help in your case, too). But with harder, fine-grained woods it will probably be fine.
You may be worrying unnecessarily. Just have a practice run on a bit of scrap, it will probably all go much more easily than you expect.