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hey all, well im coming into the home stretch of no. #1 and i've hit a bit of a dilema. im trying to figure out what kind of finish to apply. I am literally building it in my kitchen since I live in a basement apt. so space is kind of an issue and also my landlord's kid has a high sensitivity to sents so aerosol's are also a big concern. its a african mahogany neck, sitka top with curly french walnut b/s. I really want to figure in the walnut to pop. So im curious what you might recommend.

Thanks alot

In a situation like that water based sounds the best. I've tried a few and finally settled on the stuff that Stew Mac sells. You can brush it on and it's dry within minutes and ready for another coat in a few hours. But there are a lot of water based urethanes to choose from.

Shellac by French Polish is the lest intrusive finish you'll ever consider. You can do it while watching TV with the guitar on your lap or the coffee table.

Lots of information all over the net on French Polishing. Check in the tutorial section here as well as do a google search for Milburn French Polish. Both will get you started off right and the rest is just practice.

Oh, and the shellac will pop the figure of your walnut great too.

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I would go with French polish as well. Shellac has a pleasant, sweet smell, and it's as nontoxic as you get for finishes (the package of apples I bought yesterday said on the package that they had been coated with shellac). Also virtually no equipment is needed beyond an old t-shirt and wool sock.

You might consider Tru-Oil for the neck--it gives a nice feel and is easy to apply.

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(from wikipedia, and I love the part about Skittles!)

Shellac' is a resin secreted by the female lac bug to form a cocoon, on trees in the forests of India and Thailand.[1] It is processed and sold as dry flakes (pictured at right), which are dissolved in denatured alcohol to make liquid shellac, which is used as a brush-on colorant, food glaze[2] and wood finish. Shellac functions as a tough all-natural primer, sanding sealant, tannin-blocker, odor-blocker, stain, and high-gloss varnish. Shellac was once used in electrical applications as it possesses good insulation qualities and it seals out moisture. Shellac is often the only historically-appropriate finish for early 20th-century hardwood floors, and wooden wall and ceiling paneling.

From the time it replaced oil and wax finishes in the 1800s, shellac was the dominant wood finish in the western world until it was replaced by nitrocellulose lacquer in the 1920s and 1930s. It remained popular in the Southern United States through the 1950s and 1960s. It continues to be a popular candy glaze for pill shaped sweets such as Skittles.

I had no idea one could safely ingest it.

Oh, btw, I am using EmTech 6000 from Target Coatings. Inflammable and for the most part, non-toxic, though I wouldn't drink it (as opposed to the use of Everclear in French Polish!)
So, yes, with Shellac, you can sit in front of your TV, polish your guitar, and polish off some EC and have a great time! EmTech 6000 has a slight odor of ammonia. Seems to me I saw in a Highlands Woodworking flyer something about a spray system that uses non-toxic propellant (replaceable) where you could easily (and cheaply) spray the finish. Just stick a box fan in the window or do it outside. Nobody will notice the smell.

Mike

Here it is, at Klingspor, not Highlands: http://www.woodworkingshop.com/cgi-bin/ ... mSt=PREVAL

I have no idea if it is any good... but I wish I had had a chance to try it before I invested heavily in spray equipment... seems a good way to learn if it is any good, perhaps better than a brush?

Mike

The Preval sucks and is a total waste of time IME.
Shellac can be brushed or applied with a rag. A FP is nice, but good results can be had without a perfect technique as long as one does not try to build too much finish at once and the finish gets leveled every other session or so.
I have no experience with waterbase finishes, some rave about the newer products, but it seems there are always problems down the line. Also waterbase does not mean non-toxic with no odor.
Oil varnishes like Behlen's Rockhard or Pratt & Lambert #38 can be applied with a brush and some good technique, and they will give a depth to the wood that no other finish can accomplish.
Tru-oil is kind of OK, too soft IMHO, and building enough finish thickness with it requires a lot of time.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

OK! Preval sucks. Had no idea and am glad to see feedback.

Laurent, question about varnishes... they are difficult to repair since the material cross links, correct? But you need more than one coat, so how much time between coatings is allowed? And what is a typical minimum time?

EmTech 6000 is considered non-toxic from a fumes point of view, but they still recommend aspirator masks. And you won't blow anything up using it. The problems with this finish as well (as I am told) with any acrylic finish is the risk of a blue hue. There are ways to mitigate this. I have never tried brushing it...

Mike

Everything except shellac and lacquer is called a varnish so… I can only talk about oil varnishes.
Oil varnish cures by polymerisation rather than evaporation of the solvent like shellac or lacquer, is that what you call cross-linkage? The problem is that, unlike solvent based finishes, the subsequent varnish coats do not melt in the previous ones, forming a single layer of coating. Sanding through one coat will expose the preceding coat that has cured a little more, thus show the typical witness lines. One way to avoid that is to add a bit of acetone in the varnish, it seems to help coats burn in. Repairs can be done by shooting a varnish mix heavy in acetone with a small touch-up gun, or an air-brush. The witness lines may appear after cutting the finish back, but will disappear with buffing. Too much acetone will destroy the varnish though. Usually it is easier and less of a headache to refinish the whole panel.
Short oil varnishes can be scuffed and recoated after 4 to 6 hours, depending on the temp and RH (the drier and hotter the better). Long oil varnishes can take up to 3 days. Oily woods such as cocobolo, Honduran RW etc. need to be sealed with either shellac or a light coat of 1:1 varnish/solvent (turps or naphtha) before applying the first full varnish coat. Otherwise the varnish may never cure and remain soft and tacky indefinitely.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I'd suggest tru-oil. The odor is negligible, it's easy to apply and get a creditable finish, and it's cheap. A small bottle costs about $9 (around here-near Buffalo, NY) and is plenty for a guitar.

Joe

When I get closer to finishing a guitar I was planning on starting a thread about the Crystalac water based product I order through McFeeleys. I have been using it for a few years on my window picture frame product. I find it odorless and easy to spray and sand. Have not brushed it but they have a product for brushing. If I apply too heavy, I see a purplish hue, but it dries very clear. I use a bit of the viscosity reducer to get it to flow with a thinner coat. I spray with a box fan behind the work and use a regular dust mask even though there is no smell.

Curious if there are any with experience with this product on instruments. I can recommend the product for general use, but have no experience using it on guitars. The label says it can be used on instruments, but that is the product's marketing guy's opinion.
Rob

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<LOL> I vote French polish <LOL> wounder why??<LOL>

That said I have had great results brushing KTM9 in the lacquered look is what you are after. Some claim to have had good results ragging KTM9, but my ragging efforts with it were mostly less than my expectations.

I second what Laurent has said.

In cases where oils in the wood have slowed the cure of Behlen's Rockhard varnish, I've found that UV light speeds things up a lot. You can get UV-CFLs that fit into normal fixtures, and they work nicely.

The witness lines are, as Laurent said, caused by differences in hardness between subsequent layers of varnish. The longer you can allow the piece to sit before polishing it, the less the differences, and the problems, will be. It also helps to build the finish fairly quickly: two or three thin coats in a day is what I try for, once the first coat has fully set up.

DON'T try to put on the second coat before the first coat is fully dry to the touch. The second coat might well seem to harden properly in that case, but the first coat will still be soft, and eventually the whole area will slough off. Ask me how I know...

I've had enough bad experineces with with water borns that I'm skeptical. Some work well on cabinets, but don't play nicely with perspiration, for example. There's nothing like having one of your guitars come back after a year or so with the whole back of the neck covered in something that looks like chewing gum to sour you on a finish.

These days, French polish and Rockhard varnish are the finishes I use, and I recommend them to my students. However, I've had students use all sorts of things and get good results.

In the end, whatever finish you settle on, it will take a certain amount of experience to get good at it. By the same token, if there's some sort of finish you're already good at, and it's not ruled out by other considerations, you'd probably do well to use that.

I have wondered about UV CFLs. Has anyone ever had success building their own cure cabinet using them (for polyester and other UV cure finishes)?

Laurent, yes, cross linking is polymerization. If the finish cross links, then there are few if any active sites for a new coat to react with. It makes them tough finsihes.

Mike

I admit waterbornes are still up in the air when it comes to the time testing results. But having used KTM and the Stew Mac stuff over the last 5 years or more so far no problems what so ever. And in the case of some guy building his first guitar in his kitchen i think it's a very good alternative to trad finishes. There is a learning curve in all finishes no matter what but I think the formulaic differences between French Polish, one part this one part that mixed in alcohol, etc... Versus ... open a can of finish and apply - is for some users a no brainer.

I like FP finishes they are awesome and totally doable but they are also IMO fussy and less durable.
I don't know it's part of the beauty of the whole thing, for some a finish is magic and works wonderful, for others (like myself) they struggle.

If your going to use a waterborne, I would highly recommend KTM-SV. NOT to be confused with KTM-9 that most people have experience with. KTM-SV does not contain any acrylic, so it does not have a blue cast and dries harder than other waterbornes, all of which contain acrylic resin.

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Randy Muth
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Funny fact of the day: inflammable and flammable are synonyms (seriously!). What will we English-speakers think of next?

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

We use EM6000 and like it very much as a main coat, but for us it doesn't make the figure pop as good as shellac. So we apply 1-2 coats of Zinsser's Sealcoat first.

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David Malicky

I use KTM 9 (have been spraying it), and contrary to some of the other opinions, I like it. I've not had the experience with the "blue haze" or maybe I'm just not looking for the right thing.

I've heard (as others have noted) that brushing KTM 9 is an acceptable approach. Definitely worth a try.

Final comment. I love shellac, and have had some success with French polish. The comments about the non-toxic nature of shellac are definitely attrractive to me as well. One thing to note is that, depending on the solvent you use (denatured alcohol - toxic) or (grain alcohol - non-toxic) exposure to the shellac can expose you to toxins. Wear nitrile gloves, and you'll be fine.

Have fun.

wow, thanks for the great response guys, I appreciate it. I was kinda split on trying my hand at french polish or just going with a waterborne. a fellow builder at Exotic in Burlington suggested oil and bee's wax which by what im seeing here seems a little unorthodox. I remember reading a topic a little while ago that using epoxy as a grain filler will really make figured wood pop. would you suggest using that and if so, would french polish or a waterborne work better. I know im ruling out oil if I go that route. im just a little lost with the abundant of choices and I just want to make a plan before I start applying anything

thanks again

I really struggled with that Bob! So, I think now the proper way to say it is non-flammable (or non-inflammable??)

Muthrs & I have discussed KTM-SV and I seriously plan to try it out soon. But my recollection is that it was a more difficult product to use... more steps, process and all of that. Also, its hard to repair (cross-linking). I have to go along with the other folks on the newbie issue in the kitchen, since water bourne EmTech 6000 is so repairable, dries fast, apparently can be brushed, coats re-melt, and is easy to level. And its non-inflammable. BTW Randy, maybe one day when you get some time you could put together a KTM-SV tutorial and post in the tutorial forum?

By large consensus using slow drying and penetrating oils such as linseed or tung oil on an acoustic guitar, especially the top, is a no-no.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/