A More Complex Veneer Repair
The side of the radio cabinet I'm restoring has a good deal of damage to its side. In this article I'll take you through the steps I took to repair that damage:
The damage is enough to seriously detract from the beauty of this 80 year old mahogany cabinet. Some might argue that a true repair might involve replacing the entire side - or at least the veneer for it. I don't want to get that involved or invest that much time into it, nor do I think there is any real reason to... While this is a fairly complex repair, it certainly is not a difficult one... It's more likely to test your patience than it is your skill.
The base material is a lumber-core veneer plywood... Essentially, it's made up of 4 plys - the main, lumber core, which is about 5/8" thick; sandwiched by some fairly inexpensive wood on the front and back, likely a softwood about 1/32" thick with the grain running perpendicular to the core and the face veneer; and finally, a mahogany veneer on the face.
The biggest problem is that the substrate ply has been damaged and is missing:
After that, a large portion of the veneer along the bottom is also damaged:
I considered a couple other options - one, cover the damage with some applique liket what's on the front, and two, to cut off the bad portion and raise the height of the side a half inch or so. Neither really appealed to me, so I took it upon myself to repair the veneer itself.
First up is to repair the substrate. Using a straightedge, I trim the end of it to form a straight line for me to work to, then clean it up to accept the repair.
The next issue is to find a suitable replacement for it. It HAS to be exactly the same depth as the original so the patched veneer over it will remain level. It's thicker than veneer, so I cant use that.... Looking underneath the cabinet, I score upon a plethora of material for the patch - the ply is coming loose off of the back of the front apron:
After taking a piece large enough for my repair, I cut it roughly to fit with a mat knife and glue it into place, replacing the missing substrate. I then mark out around the damaged areas of existing veneer, and using a sharp mat knife and straight edge, I cut out around the damaged area and remove it, cleaning up the bottom with a sharp chisel.
One should avoid patches that have line directly perpendicular to the grain - they can be too obvious. The closer you can make the cut to parallel with the grain the better, as the grain will hide the splice. You still should't remove any more veneer than is necessary either, so it's striking a balance on what will be invisible, and what can't be avoided.
Then I place a piece of high quality masking tape over the cut out veneer, with the tape running parallel to the grain (so when I put it on the new donor veneer patch I have the grain running in the correct direction), I trace out the shape of the patch on the tape using the side of a pencil.
It's important to use good quality tape so it can be removed from the veneer without damaging it. Even then, I usually put the tape on my pants first to remove some of its stickiness...
Here I've put the tape on the donor veneer patch, from an African Mahogany flitch cut purchased from Constantine's.
I cut the piece out using a quality pair of scissors, then using hot hide glue place the patch and clamp it into place with a caul, some wax paper, and a small spring clamp:
Once the caul is removed, here's the result - you can see the hide glue (dark area) around the patch:
It's no big thing to remove that excess glue - a scraper works wonders. Just be careful at the end, especially if the veneer still overhangs the edge a bit.
The large damage was too big and had too many corners and odd shapes to do all out of one piece. For that one, I simply split it into two separate patched directly adjacent to each other. I patched the area on the left first, then proceeded onto the right after that patch had dried.
It's OK to slather on the hide glue - I put this much on the veneer patch as well:
Scraping takes off the excess glue easily. I use a special small scraper I made from .015" spring steel - I find most "cabinet" scrapers to be far to thick and unyielding for small repairs.
Once the glue has dried, I remove the overhang by GENTLY using a file, and only on the down stroke as not to lift the newly patched veneer. I had to hold the camera here, but I usually have my finger holding down the veneer right on the edge to help support it. This can be a nerve racking process if you aren't careful../
After that, it's finish scraping to level the veneer and sanding to blend them together - being careful on the end not to sand through the veneer and recreate the problem I just fixed.
The repairs are certainly visible - but with finishing they should sublimate a bit more, so I think they'll be adequate.