Finish Prep

The Achilles' Heel of Luthiery
Darryl Young
Posts: 1668
Joined: Fri Jul 30, 2010 6:44 pm
Location: Arkansas

Re: Finish Prep

Post by Darryl Young »

Ken C wrote: If you are using water based finishes from Target, their shellac and EM6000 work quite well together. I have shot base coats of amber shellac on my last several guitars. Adds some nice depth to the finish.
Ken
Ken, do you shoot the amber shellac then use epoxy pore filler over the shellac?
Slacker......
Ken C

Re: Finish Prep

Post by Ken C »

Darryl, as the shellac is tinted, one needs to be careful not to sand through it or the finish will be blotchy. I do all my pore filling and prep, then shoot one or two coats of shellac. I'll then shoot 3 to 6 coats of EM6000 before I level the finish just to make sure I don't sand through the shellac. The mad rose OM and claro walnut 185 were both shot this way. If I want to seal the wood before pore filling, I'll use some thinned EM6000.

Ken

Darryl Young wrote:
Ken C wrote: If you are using water based finishes from Target, their shellac and EM6000 work quite well together. I have shot base coats of amber shellac on my last several guitars. Adds some nice depth to the finish.
Ken
Ken, do you shoot the amber shellac then use epoxy pore filler over the shellac?
kencierp

Re: Finish Prep

Post by kencierp »

Dave -- suppose I should have made that more clear -- no it is not necessary to start all over with the most course grit -- but when you spot some scrathes -- use a grit that totally removes the defect, then use the grit progression from that point. I use foam insulating material for my sanding blocks -- I do not recommend power sanding unless the builder has much experience using the tool. One other point regarding Pore O Pac filler -- the product needs to be burnished into the pores and all the residue must be removed during this process -- trying to sanding the surface after the filler drys tends to remove the product from the pores --- putting you back to square one. And leaving any filler on the surface results in the cloudy look so many fear and associate with paste filler.
Darryl Young
Posts: 1668
Joined: Fri Jul 30, 2010 6:44 pm
Location: Arkansas

Re: Finish Prep

Post by Darryl Young »

Ken C wrote:Darryl, as the shellac is tinted, one needs to be careful not to sand through it or the finish will be blotchy. I do all my pore filling and prep, then shoot one or two coats of shellac. I'll then shoot 3 to 6 coats of EM6000 before I level the finish just to make sure I don't sand through the shellac. The mad rose OM and claro walnut 185 were both shot this way. If I want to seal the wood before pore filling, I'll use some thinned EM6000.

Ken
Ok, so you apply the epoxy to bare wood. I was curious if you used shellac, then epoxy, then shellac. Freeman, or someone, stated on another post that they read where shellac didn't adhere to epoxy well (best he recalled) so I was curious if you had any issues.
Slacker......
Freeman

Re: Finish Prep

Post by Freeman »

I don't know where I read that, but LMI say no problems with shellac over Zpoxy

Then finish with KTM9, de-waxed Shellac, lacquer or urethane. Though no builders have reported adhesion problems to date, O’Brien recommends using a coat of shellac between the Z-poxy and the top coat for added insurance and always test on scrap when using new products.
naccoachbob
Posts: 477
Joined: Thu Dec 03, 2009 9:25 am
Location: Nacogdoches, Tx

Re: Finish Prep

Post by naccoachbob »

Ken C wrote:Darryl, as the shellac is tinted, one needs to be careful not to sand through it or the finish will be blotchy. I do all my pore filling and prep, then shoot one or two coats of shellac. I'll then shoot 3 to 6 coats of EM6000 before I level the finish just to make sure I don't sand through the shellac. The mad rose OM and claro walnut 185 were both shot this way. If I want to seal the wood before pore filling, I'll use some thinned EM6000.

Ken

Darryl Young wrote:
Ken C wrote: If you are using water based finishes from Target, their shellac and EM6000 work quite well together. I have shot base coats of amber shellac on my last several guitars. Adds some nice depth to the finish.
Ken
Ken, do you shoot the amber shellac then use epoxy pore filler over the shellac?
Ken, do you use shellac for the color, or is there another reason for using it?
I was hoping on my current build to seal with Emtech 6000, then pore fill, then continue with the Emtech 6000.
Thanks,
Bob
Ken C

Re: Finish Prep

Post by Ken C »

Darryl, The great thing about shellac is it sticks to almost anything! I don't use zpoxy or epoxy, so can't opine on that. I know you have commented here and elsewhere about popping grain, but note below how the grain pops very nicely under my waterbased lacquer without using zpoxy.

Bob, I use shellac as a base only because it adds a bit more depth to the finish and gives the finish a touch more of an aged look. No other reason. I typically spray it on everything but the top. However, on the mad rose OM I built, the buyer wanted the red spruce top to look more aged. He didn't want it bright white. So I shot a couple of coats of shellac on the top when I shot the body.

I know it might be hard to tell the difference in these pictures, but the first guitar is my SE Asian RW OM. It does not have a shellac basecoat. Notice that even though the finish is perfectly clear and glossy, it doesn't have the same depth and warmth as the madrose and wally. The next image is of my claro walnut FB-185, which has the shellac basecoat. Following is the mad rose OM also with a base coat of amber shellac.
SE Asian OM 140.jpg
IMGP3042_1.jpg
MadRose OM Finished 024.jpg
Note that none of these guitars were stained. The only color added is the one or two base coats of amber shellac. I think the shellac really gives the guitars a warmer, aged look. It is no harder to apply than a coat of lacquer, and if you don't like it, sand it off! Personally, I'll likely be shooting a base coat of shellac or tinted EM6000 on the majority of my guitars going forward. I am now in the process of spraying my EIR/lacewood OM and my sunburst Les Paul. These are going to get EM6000 tinted with honey amber. I have the burst done on the LP, and am ready to shoot all the clear coats. The plastic bindings on the LP are just too white for my liking, so I am shooting the tinted EM6000 to soften them up a bit and again give the finish some depth. If I can ever get a half dozen evenings with low temp, low humidity, and some time, I could finish spraying both of them!

I'll add one last comment. The process I use works very well for me and suits my tastes. I have spent a lot of time working with Target's coatings developing an approach that gives me results I like and is repeatable. It is by no means the only way, and every finisher you talk to will give you a different 'recipe'. The best way to figure out what you personally like is through trial and error. If you don't want to experiment on your just finished guitar, grab some scraps from when your trimmed the back, and experiment on those. All it will cost you is a little time.

Ken
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Darryl Young
Posts: 1668
Joined: Fri Jul 30, 2010 6:44 pm
Location: Arkansas

Re: Finish Prep

Post by Darryl Young »

Thanks for that post Ken. I mistakenly had thought you used zpoxy as a pore filler on the Madrose guitar. I'm curious what you use for a pore filler?
Slacker......
Ken C

Re: Finish Prep

Post by Ken C »

The madrose was largely filled with Target's High Solids Filler, but I also did some followup in certain areas with CA. Target's HSF has been sort of an 'on again off again' product for me. I like the fact it is clear and can easily be tinted, but I find it a bugger to work with. With silica powder it behaves a bit better, but it is tough get that stuff worked into pores, and anything on the surface has got to be sanded off or the finish will look blotchy. And, it is also a real pain to sand. I also use Pore O'Pac, a product I used years ago, and am gradually using again more frequently. I have used it on two guitars and typically use it on all my necks.
Darryl Young wrote:Thanks for that post Ken. I mistakenly had thought you used zpoxy as a pore filler on the Madrose guitar. I'm curious what you use for a pore filler?
lnjguitars

Re: Finish Prep

Post by lnjguitars »

Ken C,

The finish on that MadRose OM is flippin beautiful! Do you have any other pics of the guitar?

Brad
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