Spraying Shellac - Page 3

Victory Pete · #31 04-26-2021, 06:25 AM

Quote:

Originally Posted by RoyBoy

Lighting aside, your last pictures of the guitar show inadequate atomization and poor flowout. You'll end up sanding almost all of your finish off to get it level.

To spray finish, you need a compressor that pushes enough CFM to drive a full size gun, or at least a touch up gun. Your woodwork on the guitar looks real nice though.

Well it is a learning curve with the new gun. The new gun I have has a 1.4 mm needle and I have a smaller gun with a 1 mm needle. I am pretty sure I can get a better spray with practice.

Victory Pete · #32 04-26-2021, 07:25 AM

The guns I have are HVLP, I have been wanting to get an AM-8008/5008 “SmartPak” combo. Since these are LVLP they may be just what I need.

https://homesteadfinishingproducts.c...guitar-making/

Victory Pete · #33 04-26-2021, 11:12 AM

Just ordered the AM-8008/5008 “SmartPak” combo.

Victory Pete · #34 04-26-2021, 11:15 AM

Quote:

Originally Posted by RoyBoy

Lighting aside, your last pictures of the guitar show inadequate atomization and poor flowout. You'll end up sanding almost all of your finish off to get it level.

To spray finish, you need a compressor that pushes enough CFM to drive a full size gun, or at least a touch up gun. Your woodwork on the guitar looks real nice though.

I started with Preval sprayers so a rough surface seems normal to me. I have a bigger compressor in my workshop but would love to keep using my small Paasche compressor.

Victory Pete · #35 04-27-2021, 12:08 PM

I now have 8 oz of shellac flakes down. It is fairly thick. I have a method of determining thickness by using a flashlight, you can see a halo of light and get an idea of how thick it is. The low shiny spots are getting smaller and I will be switching to a softer foam block to do final level sanding when this is dry. My new guns are coming tomorrow so I want to be able to put down the final finish coats with them in a couple days.

Victory Pete · #36 04-27-2021, 04:57 PM

I get fidgety in between coats of shellac, this venture turned out great. I get way more CFMs for less RPMs. Just clears window when closed.

runamuck · #37 04-27-2021, 09:41 PM

Quote:

Originally Posted by Victory Pete

I have a method of determining thickness by using a flashlight, you can see a halo of light and get an idea of how thick it is..

Can you explain how that works?

Victory Pete · #38 04-28-2021, 03:04 AM

Quote:

Originally Posted by runamuck

Can you explain how that works?

If you place a small flashlight like that one on an unfinished guitar surface you will see no light. When there is a bit of finish on the guitar the finish material, if transparent, will illuminate a ring of light. The thicker the finish the more light you will see. I do have to estimate the thickness as I have no way of knowing its actual thickness in a measurable amount.

runamuck · #39 04-28-2021, 11:37 AM

Quote:

Originally Posted by Victory Pete

If you place a small flashlight like that one on an unfinished guitar surface you will see no light. When there is a bit of finish on the guitar the finish material, if transparent, will illuminate a ring of light. The thicker the finish the more light you will see. I do have to estimate the thickness as I have no way of knowing its actual thickness in a measurable amount.

Thank you for that.
If I understand you correctly then, all you know is that there's a thickness but you have no idea what that thickness is. I don't see how that is helpful.

Victory Pete · #40 04-28-2021, 11:51 AM

Quote:

Originally Posted by runamuck

Thank you for that.
If I understand you correctly then, all you know is that there's a thickness but you have no idea what that thickness is. I don't see how that is helpful.

I have an idea if it is an appropriate thickness.

mirwa · #41 04-28-2021, 10:02 PM

Quote:

Originally Posted by runamuck

all you know is that there's a thickness but you have no idea what that thickness is. I don't see how that is helpful.

Yep.. I think if anyone at home wanted to measure material thickness on a build or respray, then something like these may help, just a set of super cheap throat calipers ($30) would IMO be a better choice than a light on the top, they cannot get to the back of the guitar but it is at least something measurable / quantifiable

Personally, if I need to measure material thickness then I use the magi probe setup, cannot speak highly enough of the product.

Victory Pete · #42 04-29-2021, 03:48 AM

Quote:

Originally Posted by mirwa

Yep.. I think if anyone at home wanted to measure material thickness on a build or respray, then something like these may help, just a set of super cheap throat calipers ($30) would IMO be a better choice than a light on the top, they cannot get to the back of the guitar but it is at least something measurable / quantifiable

Personally, if I need to measure material thickness then I use the magi probe setup, cannot speak highly enough of the product.

I have may sets of calipers and micrometers. That would only restrict you to taking measurements around the soundhole. With my light method I can go anywhere I want. Thickness of material varies depending on the amount of leveling that needs to be done. Most importantly the light will show me if I am getting close to a sand through. Your links do not show up on my page other than a little file symbol. If you are linking to an expensive thickness meter, I have one of those on my wishlist.

Talldad · #43 04-29-2021, 04:44 AM

Just been looking on your website Pete, love your removable go bar press, real meaty threaded bars on there. I did similar but I got so annoyed with constantly winding 8 nuts up and down that I drilled holes and used split pins instead.

On measuring lacquer thickness I might just try your method. Previous I’ve just sprayed a 6” square blank at the same time as the work of I needed reassurance.

Victory Pete · #44 04-29-2021, 04:57 AM

Quote:

Originally Posted by Talldad

Just been looking on your website Pete, love your removable go bar press, real meaty threaded bars on there. I did similar but I got so annoyed with constantly winding 8 nuts up and down that I drilled holes and used split pins instead.

On measuring lacquer thickness I might just try your method. Previous I’ve just sprayed a 6” square blank at the same time as the work of I needed reassurance.

I never thought of spraying a blank sample, that is genius.

Victory Pete · #45 04-30-2021, 09:36 AM

I am spraying with the new LVLP QualSpray guns. They spray nice at 29 PSI. I got ahead of myself spraying the back and got a wide run, the whole width of the guitar. I am used to spraying on my flat dolly and was going to again for the final coat but wanted to see how this would go. As things usually go around here I improvised a workaround. A plastic coat hanger hanging from the lights. I think this will be part of my technique, Spay & Hang.