Renewing nitro varnish - Page 2

mirwa · #16 04-13-2019, 05:52 PM

If you are seeing scratches in your final finish, i am making an assumption your not sanding / buffing the final finish.

More thinners gives a shinier finish but also creates more sink back, fresh less than a week old finishes sink back further with fresh nitro on finishes 1 month old.

Gloss of the gun with no follow up sanding is hard

Steve

runamuck · #17 04-13-2019, 06:23 PM

Quote:

Originally Posted by Quickstep192

Steve,

I’ve found that if I sand with anything less than 1500 that I can see the sand marks through the finish. Ant thoughts on where things are going wrong for me?

If sand marks are coming through the finish, you haven't applied enough finish to fill the scratches - OR - the scratches are in the wood.

Are you using a rattle can? If so, those don't spray much thickness on each coat so it takes many more coats..

viento · #18 04-13-2019, 06:44 PM

I guess spraying several times and sanding when dry would even help with scratches in the wood...?

mirwa · #19 04-13-2019, 06:56 PM

I sand wood with 220grit, nothing finer, be it nitro, varnish, 2 pack, uv, no scratches visible to the human eye on completed job.

The important thing is to make sure the final sanding (220 for me) goes with the grain not against it.

Steve

runamuck · #20 04-13-2019, 07:27 PM

Quote:

Originally Posted by viento

I guess spraying several times and sanding when dry would even help with scratches in the wood...?

No, it won't. If there are scratches in the wood the wood needs more sanding. Finish makes them look worse.

viento · #21 04-14-2019, 02:04 AM

Some clear putty or epoxy would help filling any scratches, I think.

Rodger Knox · #22 04-15-2019, 10:57 AM

Quote:

Originally Posted by runamuck

No, it won't. If there are scratches in the wood the wood needs more sanding. Finish makes them look worse.

There will be scratches in the wood even when it is correctly prepped for finish. The size those scratches need to be depends on the type of finish being applied. For nitro lacquer, scratches from 220 grit are appropriate. Sanding finer may compromise the adhesion of the lacquer.

For an oil varnish such as TruOil, those scratches need to be much smaller, at least 400 grit and maybe 800 or 1000. The oil varnish is a thinner finish, so it needs a smoother surface to start with. It also tends to highlight imperfections as well as figure more than other types of finish.