Official Luthiers Forum!

I have started the finish on my first. Started out with Timbermate as a pore filler, with a wash coat of shellac. Well, a couple of each, to get a nice smooth finish to start with. Then, began to build up layers of lacquer. My choice was Deft brushing lacquer, for ease of access if nothing else. I read several threads on the net where people had good luck with this stuff, so I thought I'd give it a try. So now that I have my first coated in this stuff, I feel like I'm in the middle of a nightmare. After each coat, the guitar has a lovely "dipped in thick plastic" look.

According to the instructions, you apply with a brush, and do not thin. OK, fair enough. Except it didn't self level very well. Each coat has definite waves from brush strokes, bubbles, etc. So I try to sand it between coats. This is where the fun really begins.

This stuff doesn't sand like the acrylic lacquer I'm used to. It sands more like rubber. I actually have to use 220 grit between coats just to get the surface level again, and at that, I don't get sanding dust. I get little strings of rubber, more like what I used to get with plastic eraser dust. Takes forever to get sanded back flat, but once the brush stroke waves are gone, then I can switch to 320 and 400 to smooth it out.

Now my thought was, between coats, if necessary, I would maybe wet sand with 800 grit or so if needed. But I find myself going all the way back to 220 each time, fighting that rubbery surface.

Is this normal for a brushing lacquer? I've never had good luck before using Deft, but for other reasons. And this might still work, but the rubbery surface surprises me. Is this normal? Any help much appreciated!

_________________
Phil

http://www.oleninstruments.com

"Those who tilt at windmills are only considered insane by those who can't see the dragon."

I don't know anything about brushing lacquer, but it sound to me like you aren't waiting long enough before sanding. Also, There's no reason to sand beyond 220 or 320 in between coats. The lacquer will melt into the layer below it as it's applied.
When I spay lacquer, I'll let it set a couple of day before level sanding and the another day or two to let it gas off further before spraying again. It's easier for thin finishes to gas off than thicker finishes. You may have to wait quite a while before sanding a brushed finish. But then again, I know nothing about brushing lacquer.

_________________
Jim Watts
http://jameswattsguitars.com

Deft brushing lacquer is usually very forgiving -- could be a bad batch of Deft, bad shellac, or maybe not enough drying time. Then again wet sanding may be the answer. Here's a very good Deft application video, I've known Tony for a long time he does great work!

http://acousticguitarconstructionforum. ... 2819#p2819

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

My experiences with deft brushing lacquer are that it takes forever to dry and never really gets as hard as conventional nitro. The rubbery feel when sanding is a good indication that it has not dried enough between coats.

Personally I have had very bad experiences with Deft overall and avoid the stuff like the plague.....

_________________
Brian

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

https://www.howardguitarsdelaware.com/

Deft is horrible stuff. Since you don't have a spray rig get some Tru-Oil or use french polish.

Early on (way back 30-40 years) we used Sherwin Williams Water White lacquer and Deft Gloss for furniture and musical instruments. Family members have some of those objects and they look just fine -- Now we did spray but never had issue with drying, leveling or polishing. Today I know of plenty of Deft (brushed and sprayed) users that are very pleased with the results -- so perhaps its like many of our processes, it takes time and a little acquired skill to get it right.

Because brushing lays down so much material and this formula has retarders it would seem drying time is the culprit here. I know its very wasteful but I would suggest switching over to the rattle cans to complete this project.

All that said, I agree there are better nitro products and top coating product in general -- but read the posts in the finishing sections on the various forums nightmare stories abound with just about every product used today.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

you can achieve a very nice gloss finish from rattle can nitro lacquer, and there is probably a matte or satin product in spray cans as well

Stay away from Deft rattle can lacquer.
It will never get hard and it is not compatible with real nitro lacquers.

_________________
wah
Wah-wah-wah-wah
Wah

Here's recent photos of one of my David Russel Young models I built 40 years ago -- Deft Semi-gloss -- I respect your guys opinions but I have used many gallons of Deft and had virtually no problems and never a problem with it not drying -- no, I take that back I applied it over an oil stain that was not completely dry and did have to strip it.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

Here's two of Tony Costas' I believe are brushed on Deft Gloss -- not too shabby!

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

Hey, thanks for all the replies. What a can of worms here. Only question is, are they good to eat? Some say yes, others say no. That being said, here is a side note for today's comic relief:

Yesterday, out of pure frustration, I decided to put on a coat of rattle can lacquer, of the automotive variety. So I sanded down the back, got set, and pressed the button. Whoops doesn't describe it. The can of lacquer was not clear, it was white paint!

So, today all is sanded down again. Found out I actually got a decently thick coat on the back, in spite of sanding off all those brush strokes. But, with all the brushing, I sanded too many places on the sides back to bare wood getting rid of runs.

From all the replies, it seems the one consistency is that I have not allowed enough cure time. Other than that, some have great success, some hate it with a passion. I was leaning toward the hate it ranks, but decided this far into it, why not give it one more try. At least for the sake of experiment. If it fails, then I'd have to take it back to bare wood anyway, so why not? So, today I got a can of Deft base coat sealer, and a rattle can (yes, I Made sure it was clear this time!) So I will see how this goes. After all, this is a learning experience for me, eventually I'll save lots of time by knowing how many different things don't work, right?

So, as the saga continues, I'll keep posting my progress. But for now, I decided I'd post a few pics. These are after the first coat of lacquer, I was so encouraged! But from one, you can see how much better it went on the sides, as the back shows all the brush strokes.

_________________
Phil

http://www.oleninstruments.com

"Those who tilt at windmills are only considered insane by those who can't see the dragon."

Have any idea how much the formula in that can has changed in 40 years?? It ain't the same product in there anymore! The resin formulas have been changed to work with different solvents. EPA regs have mandated that....... Even my professional formulas that are not available to the general public have changed just in the pat two years....... I have used many many gallons of finish over the last 40 years myself from all the major brands and stand by my statements on Deft brand lacquers.

_________________
Brian

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

https://www.howardguitarsdelaware.com/

From the pictures it looks like you are doing a good job of learning finishing. Spraying can apply much more evenly thin layers than brushing. Spraying or brushing another layer should generally not be done until you can't smell the solvent from the last layer when you put your nose close to the guitar. The last rule was made to be broken, but usually being in a hurry will end up with a guitar that will smell for months instead of for days. Try following that rule and don't sand until you can't smell the solvent. Sometimes it takes weeks.
The easiest materials to learn with are shellac and nitro lacquer. You can always fix your mistakes. I don't know if Deft is nitro or not, but he manufacturer surely knows, if their website or customer service person can't tell you I would be amazed. Lacquers can have additives to make it tougher (and softer unfortunately). Lacquer made for brushing will typically have additives to make it dry more slowly, so brush marks will flow out.
Once you find out what works for you, stick with it. If you are thinking of getting a compressor and spray equipment, you'll be in control of spraying thin layers that make everything go faster. Brushing is going to take more patience.

Amen to that!

Deft gloss is nitrocellulose "brushing" lacquer, its has slow evaporating solvents to help flow out. Unfortunately that is a double edged sword. As indicated drying time in inhibited as well and if not taken into account -- resulting issues can be frustrating at best. Here's the MSDS ingredients looks pretty much like other nitros -- it is not acrylic.

http://www.homedepot.com/catalog/pdfIma ... 9f8a31.pdf

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

What a treat it must be to be able to inspect your work from 4 decades ago.

A few years back my father had an aortic aneurysm and had to have surgery. The surgeon was the same person who had put in his artificial valve 20 years prior. Same thing. How amazing to inspect your work after all that time.

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

Had not thought about that but you are correct. I believe that my progression in the craft was fairly normal. Back then this was strictly a hobby and I suppose like most of us, friends and relatives were the testing grounds. One of my daughters has my very first effort -- what a piece of crap!

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

I love the look of those other guitars, very nice!

So, in general, how much time does it take to finish a guitar? I'm thinking from starting the pore fill to scraping the finish to glue on the bridge. Days? Weeks? Months? For all the stuff I've made, a fully gloss finish is new to me. My normal finishes are satin, applied with a cloth, either shellac or poly. I was once in a bind to make a show, and finished a dulcimer in under a week. yeah, not gloss guitar good, but equal to or better than any other finish at the show. I've used a lot of lacquer on car parts, but not wood. So I was thinking maybe 3-4 weeks, then I could start making the bridge. Now I am two weeks into it, and I have no idea how long this will take. Makes it kind of hard to plan ahead, but that's the way we learn.

_________________
Phil

http://www.oleninstruments.com

"Those who tilt at windmills are only considered insane by those who can't see the dragon."

Look on page 5, it lists Alkyd resin at greater than 3%. Making it an acrylic formulation of some sort......acrylic lacquers still use nitrocellulose as a base resin because it is still fairly cheap.

_________________
Brian

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

https://www.howardguitarsdelaware.com/

Brian,

What is the difference between nitro and acrylic? I have no idea, but want to learn. And which is better for instruments and why? My recent experience with lacquer on car parts is what is made by Dupli-Color, available at auto parts stores. It dries quickly and sands very easily. Will it work on instruments?

Thanks for the good insight!

_________________
Phil

http://www.oleninstruments.com

"Those who tilt at windmills are only considered insane by those who can't see the dragon."

+1 on the rattle can nitro. If I ever have to use Lacquer I go for the Stew Mac Color Tone stuff. With some experience you can get a very professional finish with the stuff without investing in a lot of equipment and space.

I've never done brush on lacquer before but I have done lots of other brush on stuff, in fact it's mostly what I do whether it was water based (years ago), shellac, or varnish. The trick to getting the brush marks out is thinning. So just get what ever solvent matches up with your finish and mix it down a bit before brushing on.

Nitro is made from natural fibers, mainly cotton, which are combined with nitric acid and a thermoplastic resin can be extracted. Celluloid is the oldest known plastic. Acrylics on the other hand are made completely from chemical stock and generally are a class of compound known as polyesters. Here is a link to an article where I go into a bit more detail on this http://howardguitars.blogspot.com/2015/02/air-dry-lacquers.html


Which is better?? That is a matter of opinion that is sometimes hotly debated. Both are thermoplastic based resins and in general are compatible with eachother. I am a firm believer that any finish that can be used on wood is suitable for guitars. To me and my ear there is no magic in nitrocellulose lacquer. Modern coatings are more wear resistant and stay better looking longer without crazing and checking. Nitro's only real advantage is in ease of application, and even that is debatable when compared to the newest UV cured products......but for the average hobbyist type it is about the easiest finish to apply that will give that nice smooth shiny high gloss finish we want.

_________________
Brian

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

https://www.howardguitarsdelaware.com/

I am not a professional guitar finisher like Brian, but I totally agree. If the time is taken to assure that all the chemicals used in the process are compatible good result can be expected. Not to say that there is not a learning curve and the need to acquire some applicable skills. I always warn against using a newly completed project as a test bed. Practice on some similar materials (which can be done while the instrument is in construction stages) its time well spent.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

I'm not a very experienced pro either. But I do know that you should choose and stay with one finish, get the hang of it. I've been using Mohawks instrument lacquer for several years with success which came with a learning curve. I would never attempt to brush on any lacquer as it is vitally important to apply each coat as evenly as possible. This will help prevent sand through in areas where you have application problems. IMHO find a compressor and purchase even an inexpensive spray gun. Harbor Freight sells an inexpensive automotive touch up gun which has an acceptable pattern. With the compressor you'll need a moisture- oil trap and pressure regulator as well. Most of the time spent using nitro is in waiting for it to cure, or gas off, between coats. Relative humidity of your spray environment (outside?) is important. If it is wet add a retarder (as a thinner) to slow down the flash or cure time to help prevent blushing. If it does blush you can spray a light coat of a mixture of lacquer thinner with retarder which will allow the trapped moisture to escape.
Sounds like fun, right? Just like any thing it's a learning curve. Buts it's rewarding when you get to the downhill side of the curve. It's important to remember to allow nitro time to cure before you start final sanding and final buffing to get that liquid like sheen. LMI and Stew Mac both have finish schedules and instructions for nitrocellulose lacquer on their web sites.
If you're not into all that trouble, go for French polishing or try Royal lac.

Sent from my iPhone using Tapatalk

_________________
"It is easier to fool a man, than it is to convince him that he has been fooled"
Mark Twain