Finish Question

[bullrun6]

I'm hoping one of you fine people out there can give me a hand...I have finished staining my latest (#5) and am ready to put the finish on. All of my previous projects have been done with Tru-oil, this time I want to try lacquer and have decided on using Deft in a can. I did a search and found some opinions pro and con but based on my limited facilities (yes, both mental and otherwise) decided Deft was my best option.

Here's what I need help with...can someone lay out a simple process for doing this? I have sanding sealer and a can of Deft clear gloss. How long should I wait between coats? How may coats should I use? When should I sand? Should I wet sand or dry sand? What grit sand paper? etc etc. I know this can be a complicated process but was hoping one of you more experienced builders could break it down for a knuckle dragger like me. I'm getting close to the finish line and am terrified of screwing it this close to the end.

Sorry about the long winded question but any and all help would be greatly appreciated. Thanks

Patrick

(Terrified in Va)

[Dale Ludewig]

I can't answer all your questions, but I'll try to help. Every builder has their own way of doing the finishing process. I think you're going to have more difficulty getting good "flow out" using an aerosol can than a spray gun. Aerosol cans don't atomize the finish as finely as spray equipment and it is easy to get what is referred to as orange peel, where the surface resembles the surface of an orange. This requires more sanding to level the surface.

Stewart-MacDonald sells a guitar lacquer in an aerosol that might be a better choice. It's still an aerosol but the lacquer may be formulated more for musical instruments than Deft, which might be more brittle. They also recommend a video they sell that covers spraying with aerosols. Since this is your first go at this, it would probably be money well spent, although I haven't seen it, nor tried their aerosol lacquer.

I spray with an HVLP gun and use MacFadden lacquer. It has great build. I recoat after about an hour to an hour and a half, depending on conditions. Regardless of how you apply the finish, I wouldn't sand at all until you've got 4 coats on and it's sat at least overnight and then you must be very careful to not sand through the finish (and the sunburst) around the edges (or anywhere else for that matter). I use 320 grit dry until I've got all the coats on, sanding between every few coats. How many coats total depends on what you want. I don't know how the aerosol lacquers sand. MacFadden's sands like a dream. After I've got all the finish on, I wait at least 10 days to 2 weeks for it to cure. Then if I'm using regular sandpaper, I wet sand starting with 1000 grit, and move up the grits through 2000 grit, and then go to the buffing wheel using buffing compound. An alternative to the buffing wheel is to use McGuire's products, available at auto supply stores.
I hope that helps a bit. Good luck!

[sunburst]

I've never tried the Deft spray lacquer, but here's what I would try and I think will work.
I probably wouldn't use a sanding sealer, just because I never do, but the procedure would be the same for your first coats whether sanding sealer or lacquer.

Ok, you have your mandolin stained and your bindings cleaned, and you know how you're holding your mandolin to spray it, spray on a coat, being sure it's not too wet! If you let the first coat get too wet you can bleed your stains onto your clean bindings. Don't worry if the coat is too dry, just make sure it's not too wet.
Let that coat "flash off". That means wait 'til the solvents have evaporated. I don't know how long with deft, The McFadden that I use as well as the Martin lacquer that I sometimes use for repairs takes less than 10 minutes, usually, unless the weather is forcing me to use a lot of retarder.
You can spray a scrap of wood at the same time as your mandolin and wait 'til you can touch it without getting any lacquer on your fingers - preferably gloved fingers.
Spray another coat, still being careful not to run or sag the lacquer, wait again, and I would spray one more, tho the books usually say to spray two.

Leave it over night and sand the next day. Sand very lightly! just enough to smooth out the rough fuzzy surface caused by the grain of the wood soaking up some lacquer. Don't try to sand the surface flat or try to sand all the gloss away, you'll likely sand through somewhere.

The subsequent coats are pretty much the same, but you have to spray the right amount of material to get it to flow out on the surface but not run or sag. Use good light so you can see what you are doing and don't worry too much. If you do get a run or sag, you can fix it later. I spray three coats per day and sand with 220-grit or 320-grit stearated paper. The stearated paper helps prevent loading, I don't know how much of a problem that will be with the Deft, but have plenty of sandpaper on hand.

You'll need to come up with some way to fill all the little pits, gaps, and pores that show up as the film builds. A good way to do this is to have a small jar of lacquer that has evaporated down to a heavier consistency, and a small artist's brush. you can brush some lacquer on the low places to fill and build them up without generally making your film thicker.
There are lots of other tricks, but I'll not go into them here.

It'll probably take 3 or 4 days of spraying and sanding to get the surface filled and level. When it is, set the mandolin aside for as long as you can. A week is good, two weeks better.

To buff, I start with 400-grit water proof sandpaper and wet sand through the grits to 1500-grit.
For the actual buffing, I usually use 3M buffing compounds, but the Mcguires seems to work better for hand buffing.
Also, now days you can use Micro Mesh. It's just like more wet sanding, but the grits go all the way to 12000 (!). I haven't tried to buff a whole instrument with Micro Mesh, but I've been pleased with the results on repairs when I'm re-establishing a gloss. The 8000 grit will match the gloss on a Martin guitar, and the 12000 and a hand polish will give you as much gloss as you can imagine.

Watch out for corners throughout the process. It's easy to sand through or buff through corners at any time.

Good luck...and...have fun!

[Mike Handley]

... and for yet another finishing procedure visit the Guitar ReRanch site at www.reranch.com and read ReRanch 101.

Like everyone else stated, wait at least two weeks before final sanding and buffing. The waiting will drive you insane.

[bullrun6]

Thanks everyone. Sunburst, that was exactly what I was looking For! Now I have an outline to follow. At this point I am very pleased with my results and I'm terrified of ruining 3 months work. I'll give this a try and post photos when I'm done! Thanks

Patrick

[thistle3585]

Patrick,
I spray a lot of Deft in my woodshop but not from the aerosol. The aerosol cans are much thinner than using a conventional spray system and more likely to run. Also, be sure to mix it thoroughly before using. If you don't then the accelerant will melt existing layers. For sanding, on my products I use a green 3M style sanding/stripping pad. I've never had cause to use sandpaper in the finishing process unless repairing runs and sags. They are also a fraction of the cost of sandpaper when bought in bulk.

[Luthier Vandross]

I always seal, especially over color, then scrape.

I can't comment on the finish, I have no experience with that, but at least seal the color, so you don't muck it up scraping.

M

[Tim Saxton]

I finished in deft and here is what I found.

I had never used any other types of finish. I have had plenty of experiance using a spray gun and rattle cans on various automotive projects.

I used the Deft sanding sealer after my waterbased analine dye had been applied. Sanded to a level finish, cleaned and applied the Deft Clear. Take note here. The Deft clear has no ball in the can. It does not rattle at all. It comes out and goes on very smooth and even. It dries to a very nice gloss.

Here is where I screwed up. According to the manufactures recomendations you can put any gloss level you want on (flat,semi, or gloss) top of each other. Not a good idea!! I used the gloss and finished it in semi gloss. This took my level and smooth finish and gave it texture. There must be a more aggresive propellant in the flat glosses can. The full gloss must have less or something.


just my $.02

Tim Saxton

[bullrun6]

Tim, thanks for the info. I have a can of Deft Sanding sealer. Do you just apply one coat? How much sanding do you do before you apply the gloss lacquer? Thanks much?

[Bandersnatch Reverb]

I've used Deft spray - it works well. The gloss, of course, is harder to apply. You need to keep EVERYTHING dust free.

Spray light coats. Dont go for gloss in the finish.. just get it coated. Wait 3/4 hours. Sand with 400 paper - this takes finesse. You want to take off the high spots on the finish, and begin to level it. Wash it with naptha. Spray another light coat...sand... again 400 grit.

When the finish is starting to level, you'll see the 400 grit is leaving more marks than the grain... time to switch to finer paper. I sand dry, frequently cleaning the paper. I end up with going to 600, 800 and 1200 grit paper. After that you can spray one more light coat, maybe another if really needed... then a final VERY light sanding wiht 1200 and buff it out.

Think in terms of at least 8 coats with deft.

[bullrun6]

As I've been preparing to start this process a couple more question occurred to me regarding sanding. When I sand between lacquer coats do I sand in one direction or do I use a circulat motion? Same question for the wet sanding and Micro mesh sanding at the end?

Thanks!

Patrick

[sunburst]

You can sand in any direction. I tend to sand "with the grain" because that's just what you do. A wood worker is taught to sand with the grain. But it really doesn't matter on the lacquer, especially when you get to finer grits and Micro Mesh. Any direction is fine.
I use a folded 1/4 sheet of sandpaper. The folded paper is stiffer than a single thickness and acts a little like a sanding block to help keep things level and smooth throughout the coats of lacquer.

[bullrun6]

Well I have the lacquer coats applied and will be ready to sand/polish in a few days. Thanks to the help of all of you it went surprisingly well, as a result however I have a few more questions...The lacquer has a nice gloss to it but has a very slight "orange peel" to it, I assume that during the final sanding this will come out? Should I be trying to eliminate this with the 400 grit? I bought some Micro-mesh (1500-12000 grit) at what grit should I switch from wet sanding to the micro mesh? Also after applying the final coat of lacquer the finish developed a milky appearence in a couple of small spots, will this disappear during the sanding?

Before starting this process I admit to being completely intimidated by the finishing process but now that I've started I'm actually enjoying it, except the 10 days I have to wait to start sanding. Thanks for all the help!

Patrick

[sunburst]

A little bit of orange peel is normal. The 400 grit will probably be about right, but you can start with 600 or so and see if it's enough. If you don't need the 400, you can skip a step. If you start with 600 and it's not doing the job, go back to 400...nothing lost.
I wet sand through the grits to 1500, but you can go to 2000, and then switch to the Micro Mesh. Thg gloss will start to show up at about 6000 grit.
The milky places are probably a little bit of blush. They'll likely go away. I would say they will go away, but there is some very small chance that they won't go away with sanding and buffing, but don't worry, they'll go away.

Take your time sanding it out and rubbing with the Micro Mesh. Don't hurry. Keep a dry towel handy and wipe off the water regularly to check your progress. Avoid corners and other places that are easy to sand through. If you try to do the whole process in one sitting, it seems like a lot. Take a break if you're getting impatient or tired.

Good luck, have fun, post pictures!