MIMF

Just wondering how other people do this...I have quite a lot of repairs to do that require filling additional routs, ie a Vintage Strat that's been routed for humbuckers or filling extra cavities that have been cut for different bridges or switches etc. Generally my method is to rout out a neat cavity then make a block to fit, glue it in place and plane/sand smooth and refinish. I only use cellulose products for finishing as nearly all my work is on vintage stuff BUT find it almost impossible to completely hide the repair, even if perfect after spraying and polishing after a few days the repair will faintly appear in outline again....Wondering what other peoples methods are regarding fitting the repair block and preparation for paint.

Many thanks
Chris

I let lacquer cure for a month before leveling and polishing since it continues to dry and shrink for several weeks.

Not only the lacquer can shrink, but the wood also.
Any wood I use for repairs like this has been sitting in my shop for a long time drying.
Grain orientation has a lot to do with this too.
I'm sure you know this already though.

Yes, I find problems with both the wood shrinking/expanding and lacquer "sinking"... Even after the finish has been on for a while and I've sanded back and polished after a while an edge will show and even re coating with lacquer will soften up the existing coats and start off the whole problem again.... I was wondering whether it's worth making the repair lower and applying a thin layer of car filler? or if using a different undercoat locally would help. I know that a lot of car repairers even when doing vintage cars with cellulose will use a twin pack undercoat to avoid sinkage around filler etc.... Anyhow thanks for the help so far.

I assume you are using opaque finishes? If so, bondo or car finishes might be an option but this stuff is not in my wheelhouse so I can't really make any recommendations.