Official Luthiers Forum!

Hey folks,

Firstly, I found this helpful - https://amo-csd.lbl.gov/downloads/Chemi ... Gloves.pdf

Second, a question - I wanted to use a mix of isopropyl and water (50/50) as a degreaser when sanding finish topcoat. The autobody folks recommend wiping between each grit just to clean the surface and prepare it for the next grit.

When using this recently I noticed that the orange nitrile gloves I use were leaving an imprint on the finish after wiping that had to be sanded away. I’m wondering what that is, but more importantly, does anyone have experience with a glove that absolutely does not react with isopropyl?

I have a suspicion it could also maybe come from the “touchscreen friendly” aspect of the gloves I’m using? I don’t know what makes them “touchscreen friendly”, anyone know?

Brad


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

What kind of finish?

I think touchscreens function on sensing a finger electrically and not pressure so maybe the "rubber" is conductive somehow.

Latex can be an allergen so some people get sensitized to it.

Sounds like something may be softening the finish.

_________________
Brian R, Wood Mechanic
N8ZED

I use the blue nitrile gloves for finishing and clean in between grits and prior to subsequent finish coats using naphtha on a paper towel. I have not noticed the issue you're having. I don't use alcohol because I usually have shellac on my guitars pretty early in the process and I would worry the alcohol would soften it or make it sticky.

_________________
Steve Smith
"Music is what feelings sound like"

Finish is UV cured polyester. I don’t think it should be the isopropyl softening the finish?

I’ll experiment a little more and/or switch to Naptha.


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

Take a look at this Brad -

https://www.engineeringtoolbox.com/chemical-resistance-polyester-d_784.html

I did not look in depth but it looks like polyester is listed as resistant in temps up to 60F (temp) for dilutions but not resistant to 100% isopropyl. So may be some reactivity there.

Further down the list it looks like poly is resistant to Naphtha and petroleum products.

Just a quick look on my part so probly needs more research.

Particular formulas of poly may have different characteristics too.

_________________
Brian R, Wood Mechanic
N8ZED

Fascinating. I thought once fully cured the polyester would be resistant to isopropyl!


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

nitrile is going to be desolved in acetone I use vinyl

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

when dealing with lacquer I've always used mineral spirits as a wash after sanding before the next coat, making sure of course to let it all flash off...never had any issues whatsoever with doing this as I've always viewed mineral spirits to be a safe product for a cured finish. never tried it with poly though but I'd suspect it would be fine as I've been using mineral spirits forever for cleaning off subfloor adhesive when it gets on any sort of finished product and haven't had an issue (that I know of) ever. and being the potential idiot I am I've never used any sort of gloves when using spirits.

YMMV of course

Thanks, Mike! I’ll try mineral spirits out. Naptha works ok but it’s getting harder to get around here.


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars