Clear Finish

[Rabbit]

First, apologies to a_novice for the hijack...



Rabbit, I've seen water based clear "lacquer" for guitars and woodworking. How would that differ from an automotive lacquer?
I'm just thinking vintage guitars were painted with auto lacquers, so wouldn't it work other way around?
FTR, I've never done any car painting and my only experience with lacquers has been on guitars.

Also, I've just been reading a bit about waterbourne automotive paints, and it does seem like the technology just isn't quite there yet. Even PPG, whom I think kind of came up with it first (???) points out its shortcomings.

With regards to clears, it comes down to durability. Auto grade clears are the highest in durability, then marine finishes a step below that. For a guitar , that level of durability isn't realy needed, but it's nice to have. As for base coats, in the auto industry, both factory and refinishing industries are increasingly making use of waterbourne technology.... your information may be a bit behind the times. The technology has improved dramatically, but it requires re-training to apply them properly.

[McCreed]

The technology has improved dramatically, but it requires re-training to apply them properly.

Yes, that was actually some of the info that PPG posted. As well as some equipment changes, but I wasn't aware that it was becoming more widely used in the industry. Thanks for info on differences in clears. I don't know why, but I assumed marine grade would be harder wearing than auto. Interesting.

[Rabbit]

I wasn't aware that it was becoming more widely used in the industry. Thanks for info on differences in clears. I don't know why, but I assumed marine grade would be harder wearing than auto. Interesting.

Yeh, besides PPG, others such as Sandox and Spies Hecker have waterbones. Much more common in smash repair places. There is more of a demand to go green, from the car re-finishing stand point, and from the paint manufactures, the US is a big market, and much like car emissions, that's driven by the laws of the state of California. The custom paint scene is also has a large waterborne cadre. The spray gun manufactures are bringing out guns specifically for the waterborne base coats, and at the same time paint manufactures are modifying their paints to work more like the solvent based products. The stuff I use now originally relied on only two colours or primer and the base coats required higher pressure and a conventional gun (no HVLP) to highly atomise the paint and lay down several light coats. Now they have many colours of primer and the base sprays in fewer coats beacuse you can lay down wet coats like the solvent base. So what took 5 coats now takes two or 3. With correct air movement, they dry faster than solvent based so you can get your coats done quicker... dry time was one of the complaints people used to have with waterbornes. The who thing gets let down by the lack of a waterborne automotive clear. They do have a UV stabilised architectural grade clear which would be suitable for guitars. It also makes a good primer/grain filler on timber.

[McCreed]

Good stuff there. Thanks!

OK... now back to you regularly scheduled program...

[a_novice]

All good!

Just trying to find the right product...the SCA Clear Coat spray can that i've used on my 2 builds so far have worked fine and i like to nice build up i get. It works really well with burying decals as well but i had much more trouble doing the same with TruOil (as i figured i would) but like the feel of TruOil on the neck.

So looking for something that i can achieve both outcomes with (building up on headstock for the decal, fast action on the neck playability and keeping original wood colouring - no amber over time).

[Rabbit]

The SCA clear should be a DIY grade automotive acrylic, so a good pick for durability. If you want fast action on the neck, I'd suggest once it's cured using either 0000 steel wool or 800 grit working down to 2000 grit wet/dry paper on the neck. I found that seemed to work for me on my DX-4. Nice shiny polished body and the neck is like butter.

[a_novice]

so sand the neck using water just like the body? or sand without the water to get the similar effect of using 0000 steel wool?

[Simon Barden]

For sanding the back of necks for a smooth satin feel I’ve always done it without water. The finer Scotchbright pads are another alternative to sandpaper and both are much superior to steel wool to avoid those fine steel splinters sticking in the finish.

[Rabbit]

so sand the neck using water just like the body? or sand without the water to get the similar effect of using 0000 steel wool?

Dry sand, although you could wet sand... I don't like wet sanding because I don't feel confident that everything is *completely* sealed and don't want to risk getting wet wood. I have used scotchbrite pad as Simon suggested, but I find they are similar to 400 grit..at least the grey ones. Good for initial smoothing, but I like to work my way through the grits up to 2000 and leave it there with no polishing. I'd suggest just work your way to what feels comfortable to you ... On a cleared neck with no paint underneath the scratch marks from the paper are less noticeable so you can get a nice satin feel with lower grits. I found on the black axe bass neck I need to go finer to make it look more even but still feel right... anything beyond 2000 grit and the clear I'm using starts to get shiny again.

[Dikkybee007]

I have been using mainly Poly on all my guitars due to drying times and the temps you can apply them. I use water based due to lack of odour but if you put it on bare wood then it can raise the grain so I put on a solvent wipe on poly first, maybe 2 coats but most time I get by with a single coat, and then finish off with water based over the top.

You can wet sand with other substances than just water. I have used Shellite near holes or cut outs but you have to be a bit mindful of your surroundings. Make sure there is no naked flames or other ignition points and do it outside as the fumes can get a little bit overwhelming and wear the appropriate mask with the correct replacement cartridges.

As for the back of a neck I use the fine white Scotchbrites as they are equivalent to 1500 and leave a satin finish that my hand doesn't stick to after getting sweaty.