"is it best to seal the wood with sanding sealer before assembly?"
I think so. Even on all the cabinets I built, the purpose of the sanding sealer was to make the soft grain "fuzzies" hard enough so they would break off during sanding, leaving a smooth finish. We have all seen wood fuzz on painted models, and one practical way to get rid of it is sanding. This could be done after assembly, but is much more difficult, or in some cases , impossible.
Now, the down side...The easiest sealer is lacquer based because it dries fast and does not load sandpaper. (a lot of sanding sealers are just lacquer and talcum powder). It goes fast and produces an excellent surface for painting when sanded with 400 or so grit. BUT ,, the sanding sealer makes a barrier for your adhesives...so even if you assembling with CA, your joints will not be any stronger than the lacquer--I guess you could imagine assembling a model with lacquer paint for glue. I find it is strong enough for most joints on a model , but not all.
Still, lacquer sanding sealer has produced such nice results for me that I continue to use it , but I scrap it off where I am gluing on things like bolsters, or little details like brake platforms ect. this can be a major pain on things like all the diagonal braces on a single sheathed car, but the next time you see a house car with a missing roof batten, you can bet they were glued on after sanding sealer.
I will keep using it because I like the results. Take scribed sheeting for instance. most all of it is way too deep, and sometimes fuzzy. I brush on one or two coats of a lacquer paint and presto the the scribes are a believable depth. Going over after with a tooth brush really cleans it all up and removes fuzz without ruining the wood grain look. That activity would not be possible with the grabs and door hardware already on .
Kind regards, Jeff 'JJ' Davies San Ramon Ca
