Official Luthiers Forum!

First time user, Target Coatings EM6000, have done a fair amount of NC Lacquer.
Couple of quick questions:

1. Does anyone add a bit of retarder to a guitar sized batch of WB lacquer (pre reduce a quart)? I did that with lacquer on advice from a finisher. I'm fixing to decant my gallon into quart cans and was thinking about adding retarder to the one I'm gonna be working from.

2. Can I spray em6000 in high humidity? About 55% was my UPPER limit with lacquer. We seldom get 4 straight days here with humidity below 55%. TC advises recoating within 100 hours of last coat to avoid the need for scuff sanding between coats.

Fun Facts:
TC advises not to use 2lb cut lacquer as a sealer; reduce it to 1lb cut. Zinsser Seal Coat in the can is 2 lb cut. ZInsser dewaxed aerosol is also too heavy https://www.targetcoatings.com/2020/08/ ... -finishes/

Attached the EM6000 and EM1000 sanding sealer TDS "just because"....

_________________
Measure Twice,

Karl Borum

I’ve used EM6000 and its predecessors for several years. I never noticed the 2 lb cut prohibition and have used a couple of coats of 2 lb cut shellac and pumice pore fill in a french polish pore filling technique, followed by a final 1 lb cut as a final sealer over the pumice without any problems over many years. I don’t think the cut of the lacquer makes much difference beyond the drying time. 2 lb needs to dry overnight before spraying with EM6000. 1 lb is ready within 30 minutes (at least within my 40% controlled shop). (The pumice fill is often disappointing enough that I don’t whole-heartedly recommend it).

I have never used retarder. I do sometimes use the cross-linker according to its directions. If you go to cross-linker, find the instruction video on the Target Coatings website. It’s informative. The cross-linker seems to help the lacquer flow out a bit and lose some of its aversion to sharp edges. You don’t need it, but I often use it.

Being lazy and not wanted to set up my spray booth, I usually spray outside the door of my shop and bring the parts into my 40% humidity controlled shop to dry. The outdoor humidity has never caused me any problems with this scheme. I don’t do this when the temperature outdoors is much below 65.

In the winter, when I don’t want to spray outdoors, I sometimes dilute the EM6000 with a tiny bit of water to thin it for brushing (a lot of brushed thin coats work pretty much like spraying).

Thank you Bob.
Today is day one, maybe I'll get 4 coats. I don't see that there is a limit on the number of coats in a day.

_________________
Measure Twice,

Karl Borum

Curious - why only 4 coats in a day?

I usually wait an hour between coats which means I can spray all 12 coats in 1 day. Between coats I hang the guitar in my heated storage closet (75°@ 38%RH). I build between 40-45% RH. If you are building in high humidity (60%RH) you may not want to use an electric space heater to heat your closet as it dries out the air pretty quickly and we all know what happens when we do that.

I use Silvertip on the back and sides and nothing on the top. I simply spray 3 coats on the top, give the top a quick sand to level to knock down any raised grain, then spray away. I never thin or retard. It may be necessary where you live, but in Western Washington, not so much. I have applied EM6k over a 1lb cut home brew shellac burst which looks fine so far. Oh - I like to let the EM6k cure for 2 weeks before leveling and buffing.

Anyway, best of luck with your current finishing project, M

Lovely instrument, beautiful finish Michael.

_________________
Measure Twice,

Karl Borum

Thank you; short and sweet, and apparently critical:
https://www.targetcoatings.com/product/ ... osslinker/

While on the site, I saw a similar note about the Retarder, in the [ADDITIONAL INFORMATION] tab, which I would not have seen if I would not have watched the Cross-Linker video; slowly mix in the Retarder 1 hour before spraying so it coalesces with the lacquer.

_________________
Measure Twice,

Karl Borum

I had an issue EM6000 on a guitar were the finish pealed off in a couple spots. I used Z-poxy as a filler and thinned the third coat with mineral spirits. Jeff Weiss at Target Coating suggested the mineral spirits leaves a film and probably caused the issue. He said to clean with denatured alcohol first. I was able to sand down the affected areas and recoat and it buffed out nicely. I don't remember who gave me the idea of thinning with mineral spirits but not doing that again.
Kent

I had several finishes fail when using zpoxy under EM6k, especially on the neck. I have since switched over to Silvertip and have had no issues. Another advantage of Silvertip is not having to sand between coats saving a bunch of time.

M

Michael, I used SilverTip to seal this one. Always glad to hear how others on the OLF are doing it.

On the Mahagony neck, I also applied Black StewMac WB grain filler over the Silvertip, then locked it in with a second thin coat of ST. It came out great on my test panels, and so far, great on my neck.

I will actually get to finish this guitar if it ever stops raining over here. Have made multiple trips to the fraidy-hole the last 4 weeks.

_________________
Measure Twice,

Karl Borum