I will be finishing an acoustic guitar. Want to use water based seal coat and topcoat for safety reasons and will apply by wiping on. Not set up to do any spray application.
Any help would be appreciated.
The absolute best sealer for wood under any topcoat is super blonde shellac IMO. It is dissolved in alcohol, so presents no safety issues unless you drink it. I would apply at least three coats, sanding lightly with 400 grit sandpaper between coats.
I can’t recommend a water-based topcoat, because I’ve never used one on a guitar. However I have used water-based finishes on furniture and I doubt you will get an aesthetically pleasing result on a guitar. Especially if you wipe the finish on.
In fact, if you are intent on using a wipe-on finish, I would just use shellac as the sanding sealer AND top coat (i.e. French polishing).
when I started my guitar journey, I bought a Fender acoustic telecaster at a great price. body was wood, not at all glossy. based on background finishing a few antique bits of furniture acquired in the hills of Southeastern Ohio, I thought I’d seal and finish it with Tong oil. I posted to a similar forum, and was admonished “do no such thing!”.
Evidently, sealing the wood can wreck the sound. I was advised to get a humidifier, keep the instrument at 50% humidity.
(eventually traded it in and got more credit than I paid for it :-))
This is an incorrect belief that unfortunately refuses to die. The idea that the finish on a solid body electric guitar will affect the sound in ANY way doesn’t make sense.
Every guitar I’ve ever handled (electric and acoustic) has been sealed on the outside with some form of finish. High-end guitars will often have nitrocellulose lacquer. Mid range models will often have a pre-catalysed lacquer. Cheaper models are often finished with polyurethane.
I have been using True Oil, normally used on Gun Stocks. I have noticed that quite a few luthiers that don’t want a paint booth use it.
I’m giving this product a go on my electrics.
Tried & True Original Wood Finish - StewMac
I’m not entirely sure if one would want to use a different product on an acoustic instrument. But I have to say that I absolutely like the feel of an oiled finish over the usual hard finishes. My Yamaha acoustic doesn’t feel half as nice as my Taylor. And my Epiphone electric doesn’t feel near as nice as that Taylor, either. Not sure exactly what Taylor uses for their satin finishes, but every instrument with a satin finish feels nicer in my hands than one with any other kind.
Of course, Warmoth says their warranty requires the use of a hard finish and that oils are a hard no. So as soon as the oil touches my Warmoth neck, my warranty is gone. But given how many luthiers like it, it can’t be that bad of a finish. I dunno if doing an epoxy seal coat first will make any sort of difference there.
You might want to check on the epoxy. I did run across a note that epoxy grain filler might not play well with True Oil, but I didn’t pursue the issue any further.
Did you decide on a finish?
FWIW as hobbist woodworker, two my favorite finishes are the tried and true products (all of these, danish oil with or without beeswax, varnish oil.
For film finishes I use shellac.