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Do any of you use a RO sander for wet sanding nitro lacquer. I've always done this by hand, afraid of sanding through with a power tool. Am I wasting my time?

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Doug

Don't let fear or common sense stop you from trying to build something

It can be done, but it sure mucks up a machine, particularly ones designed for vacuum as it will throw slurry into the workings...

If you want to power sand, you're better off going dry...

Nope, I hand sand everything. Especially when finishing, you are correct in being afraid of sanding through when wet sanding since the water acts as a lubricant keeping the sandpaper clear of dust and buildup that would normally reduce the cutting ability.

The only way I could see using any kind of power sander is in a production situation where time is critical.

I actually like hand sanding and enjoy the intimacy (if you can call it that) of being connected to what I am working on.

Bob

I have only done a couple of guitars with nitro I usually spray water based lacquer. I am a bit lazy when sanding finishes; I use a RO sander whenever I can. I sand dry. I have a vacuum attached to my sander so that grabs a lot of the dust. I start at 500 or 600 grit depending how many layers there are before the last time I leveled the finish. I do not use it on any corners or edges but I will even use it on the rims. I actually do a way better job with the ROS than I have ever done by hand. I pore fill with zpoxy and I do not spray any lacquer until the surface of the guitar is level. Once I did not have high and low spots on the guitar before spraying the finish I stopped sanding through the finish.

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Yes, I use a pneumatic. You really can't use an electric RO.
After filling and dying, enough finish is applied to level. then I sand with 600 grit and apply a second set of coats. If I have sanded through anywhere I apply a few extra coats in the area. Then I sand with 1000 grit and apply several thinned coats. I resand with 1000, 2000, 4000, and buff.
I prefer my "dust" to be in the slurry I wipe off the instrument with a paper towel.

No. In fact I rarely wet sand on guitars at all these days, only on small finish repairs that will be rubbed out by hand. Other than that I dry sand my finish to prep for buffing. I use a buffing arbor and Menzerna compounds so I only need to sand out at 400 before I start the buffing.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Brian, which buffing compounds do you use to get from 400 to gloss?

Thanks

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Josh House

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I have only seen production shops power sand a finish, but we're talking about Fender who uses 1/8" thick finishes that is impossible to sand through. There is no way I'm power sanding a finish, the amount of time it saves is miniscule to what you have to do to fix a sand through.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
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How does Fender build up to 1/8" with lacquer??... As that is what this thread is referring to.

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Doug

Don't let fear or common sense stop you from trying to build something

No. I tried using a ROS a couple of times and sanded through.

I know a lot of factories do spray thick enough (.009-.0012") and use power sanders to level sand before buffing. I also have used a dynabrade 4" pneumatic for wet sanding and it is relatively safe if you have enough lacquer.
Nowadays I shoot for a thinner finish so I like to wet sand with 600 grit and it doesn't seem to take too long to level sand.

Fender uses polyester/urethane. I've stripped one before and it takes quite a long time of very aggressive sanding to even get through the top coat.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com