Official Luthiers Forum!

Hi all,

I took a board, filled the pores with Target Coatings pore filler and then divided it into three sections. One section I French polished, one section I finished in Target Coatings Water Based and one section in Min-Wax Wipe-On Polyurethane. All three sections look pretty good and when I show the board to people and ask them what finish they like best, they have troubles choosing and say they all look very similar. So the question I have is, to some extent, me being anal.

Here's the question: Should I expect to be able to get a French polish finish as mirror like as compared to a lacquer finish? In most lighting conditions and at most angles, the two finishes I did on the board do look very similar. However, I find reflections in the lacquer finish are sharper than reflections in the French polished shellac. For example, in a reflection of a light bulb in the lacquer, I can almost read the writing on the bulb whereas in the shellac, the bulb is relatively fuzzy. Does this must mean that the surface of the lacquer is flatter. Is this just a property of French polished shellac or would you say it is more likely a deficiency in my French polishing technique?

Thanks,
Pat

PS In terms of reflection, the polyurethane is between the shellac and the lacquer.

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

I spent weekend doing test for finish also, mostly to get the zpoxy thing right, which I found not a problem, I actually used orphan back and a pretty bad to I picked up on ebay for about $10.

I did one half of the back with the the z poxy sanded all way back to wood and then sealed with shellac (of the rack can, as I don't have flakes now) the other half I sanded and then put 50/50 mix wiped on. I then used about same process on the 2 top half's.


I then took an old beat up dulcimer my wife bought on ebay about 6 years ago. It really didn't play well and looking at it I could see why. At that time I had decided I would refurbish it and make it playable. Mostly and not surprising it was a really bad job of fretting. The slots were all different depths, not level on and on. I decided I would fp this.

This is my own opinion and not something would say is best or better, but my own results and thoughts

First I think using the Zpoxy to fill is great. Easy application and for sure easy to level. I the shellac and fp process seemed easier and got a really gloss finish I could compare with nitro or other finishes. It took 1 session to be mirror like reflection. I ended up doing 3 sessions and spiriting between them and a day between. The non fill areas and just doing it worked just as well, but seemed took a little more effort. The wife is excited for the dulcimer to get new fb and to hang for about 30 days as I want it to cure more before using like I would nitro. Don't know if needed but still believe best.

The 1/2 of back with the epoxy left on and fp with shellac was about same result. The 1/2 top with the epoxy on and sprayed with nitro also was good and left a good finish and still in process of leveling and spraying it (this is last day and will let it hang same as the back that is fp before finishing the final sanding and buffing.

I am going to do the same thing with a tru oil and guess fp process finish. I have done that before and got great gloss, but slurry filled and it was harder than the shellac for me anyway. I am going to pore fill with epoxy this time.

In a previous thread, someone noted he thought or was told to seal first with shellac or whatever and the if remember right use the poxy. I tried that and it sucks up a finish as the poxy didn't seem to work on the shellac although shellac works on top of the poxy. Why things work that way I don't know or really care, it just didn't for me so that won't ever be an option, again the whys of that don't matter, just the results.

One other thing. I really messed up a board and thank goodness a test piece. While waiting for between coats on a top, I decided to clean the truck. Use some Armour All to make it all shine in areas. Not thinking and getting distracted set it on the bench. You got it. When doing a wet sand I sprayed the paper and sprayed the Armour All onto the board. I found out soon as I was sanding it just felt wrong and way to slick. I am sure this isn't or wouldn't be good on a finish, so sanded back to wood. What happens when not put stuff away and not pay attention. Just glad never did this at Bill's, as I could see myself going through the planner.

You shouldn't use ArmorAll anywhere near guitar finishes...it has a very high silicone content. I won't use it on or in my car; I don't want it on my hands, clothes, or anywhere it can migrate into my shop. Bad news...

Rick I know about the silicone, and reason scraped it. Thank goodness not on a guitar, and do it while at Bill's. I would now have been the former Stan Thomison, may he rest in peace. It was one of those "what the hell was you thinking" things and then realized, "I wasn't". I did in fact give the bottle the ole heave ho out the door and not getting any more.

Didn't know about the fact it would carry over and be a problem. Thanks. Another reason when cars needs a full detail, that is why they have businesses to do that, and better than me.

It is also another reminder of know what your doing and pay attention to detail in the shop. This was just junk piece of junk test wood, but it could have been a disaster. Also, when not paying attention to detail (learned that term at BUDS) can cause blood, pain and worse.

Pat my friend you gotta know that some jerk is going to come along and ask you to post a picture or two.

So how about it - give it up....may we see a picture....

It's been said here (OLF) before and forgive me please for not remembering who said it but it goes like this: Whom ever decided that guitars should be shiny should be dug up and shot.........

I have seen some FP jobs that rivaled a good nitro job only the look of the FP is richer looking to me and not the dipped in snot look of the thicker finishes.

Another of my favorite sayings that I heard on the OLF came from Howard and it was in the context that someone was asking if they should use their best zoot for an early guitar (notice I did not say "early build" since Howard would admonish me for using the word "build" as a verb..... ). This one goes like this - use the best wood that you have - after all it does grow on trees......

OK Hesh, here are some pics:

First the French polished shellac:



Now the water based lacquer:



Finally the polyurethane:



I think you should be able to see what I mean. All finishes look OK but the reflection of the light bulb is clearest (to my eye) in the lacquer. Somehow the differences seem more dramatic in real life than what the pictures are showing, and, as I said before, I might be being anal. Does anyone care about this besides me?

Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

I see what you mean Pat and I agree that they all look pretty good.

Nice test that you did here and thanks for sharing!

Pat,
Did you level and polish the three test finishes in the same way? You may be seeing differences in the reflections because the surfaces are just not treated the same. Note the reflection of the right side of your light fixture in the shellac finish. That area is as clear as any on the other two if not clearer.

All these finishes will level and polish up well, to a nice reflective surface. Distortion is going to come from uneven surfacing. As you try to take them to a finer polished surface, harder finishes will hold an advantage, but the softest of this lot will look darn respectable. The clarity of the finish itself, and what it does to the look of the wood it is applied to is going to differ.

All those finishes can be brought up to a high-gloss. French Polish takes a lot of skill/practice to reach a point where you can truly do a "perfect" job. It is very possible to have a French Polish finish that is truly flawless - and in fact, I can come awfully close to perfection with French Polish. I am very old school in terms of how I apply French Polish - mostly because I think that is the only way to achieve a hard film. But I do level with sandpaper and use some very light buffing compounds.

And I have to say, that having seen all the different finish types that there are few things as nice as French Polish.


--
Simon

I know I am late with this as I have been overseas but I to noticed that the wood was some what pre finished prepped different in each photo with the last being not as well filled. This makes the comparison not quite equal.

Being a long time French polisher I have to say that the photos do not show well the differences between these finishes. Your FP example the light bulb reflection is not quite in focus yet so in my opinion it still needs a good bit of glazing. When you can see the bulb in high definition, not just the light being emitted from the bulb then the glazing is complete.

I have tried targets waterborne shellac. It is a descent spray media in my opinion but being old school in terms of French polishing I did not like trying to pad it. You more or less were just brushing with a wet pad. It just has the wrong type of solvent carrier to do the job in my opinion. But it never was really intended to be a French polish media anyway.

Michael,

For the record, I prepared the whole board by trying to fill the pores with Target Coatings High Volume filler. I admit I didn't do a perfect job at this but good and evenly enough that I think you can make an accurate observation that wipe-on polyurethane (the last one you refer to as not being well filled) tends to show unfilled pores the most. A handy observation for those that want to use this finish. In terms of how the finishes were applied: The shellac I French polished on with a muneca; the Target Coatings water based lacquer (it is not a shellac) I brushed on then sanded and buffed out and the wipe-on polyurethane I padded on.

Another test I tried was to sand through and try to repair the water based lacquer. I did this because the fellow I bought it from claimed repairs could be made that would leave no witness lines. Well not by me - either I or the product failed in that regard.

So I decided to go with the French polishing for this guitar and you are absolutely correct about the glazing. With more glazing I was able to get a mirror-like shine that compared very favourably against the other finishes. Turned out to be a good decision in other regards too since the guitar dropped and now I have to fix some dings which is relatively straightforward with the shellac finish.

Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

Pat,

The claim of invisible repairs has proven to be the reason I've switched to USL. I've been using it for a couple of years now and I've made numerous repairs (mainly drop fills, but an occasional sand through) and I'd challenge anyone to find them. A couple of techniques you might try. First, if you do have a sand through, be sure your repair is executed exactly as your original prep was done. In other words, if you have a sand through on a top that you put a wash coat of shellac on before you laquered, be sure to duplicate that wash coat and let it dry just as you did when you originally prepared the surface. If it's on a back or side and you filled with epoxy originally, duplicate that process exactly in your repair. Be patient. One more trick, after you've leveled the repair, dampen a cotton cloth with denatured alcohol and wipe down the area around the repair (do the entire surface that contains the fix (the whole top, side or back) unless you're through applying lacquer. Another tip (you may already be doing this), always apply USL right out of the can. Don't thin it. You'll be much happier with the results.

These techniques have worked really well for me. Not trying to lecture you, just trying to help.

_________________
Jimmy Caldwell
http://www.caldwellguitars.com

Thanks Jimmy, I appreciate the tips. The last couple of guitars I did with KTM-9 lacquer, I sanded through when I was trying to level it out. In fact, of the four guitars I did with KTM-9, I sanded through on three of them in at least one spot. So I figure the odds are, I'd do it again. I have to say, that's one thing I really like about French polishing. I've found that you only have to sand enough to knock off any little bumps so the risk of sand through can be minimized. And even if you do, it really is repairable.

Regarding your advice, the witness lines I am referring to relate not so much to the wood under the finish but the lines I can find where the new repair lacquer meets the original lacquer. Perhaps your suggestion of wiping it down with alcohol would help with this, but as I'm doing these repairs a couple of weeks after the original lacquer has cured, I'm not so sure. I definitely will give it a try.

Thanks again for the advice. If I could make invisible repairs with the USL, that would make a big difference to my decision about using it.

Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

Jimmy,
How have your necks been holding up with USL? That's where I've seen problems.
Terry

_________________
It's not what you don't know that hurts you, it's what you do know that's wrong.

Terry,

No problems that I'm aware of. As I said, it's only been a couple of years, but so far, so good.

_________________
Jimmy Caldwell
http://www.caldwellguitars.com

I too get better reflectivity with Target Coatings (Stewmac Colortone) than I do with French Polish. Because the water-based lacquer flows it produces a smoother finish. I wouldn't waste my time with the TC grain filler, rather I like to use Z-poxy as a filler then use the sealer and top coat lacquer.

_________________
A higher purpose for wood.
Rich Smith
Issaquah, WA