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I sprayed a coat of Cardinal's Luthierlac Sealer last Friday, then a second on Saturday. When I went to level it a few days ago, the second coat started flaking away in spots. Didn't scuff between coats, which is probably the issue.

I emailed Mac, and I'll convey what he says, but thought I'd share the pic.

This is my first time using Cardinal (through an Iwata LPH-300 with 1.2 tip). So far it's been more difficult to setup the gun than I'm used to. It doesn't look as wet and I'm having trouble seeing what I'm putting down. Bear in mind I'm a guitar a year hobbiest (not a pro or semi-pro), and my reps are considerably fewer.

I'm just hoping I don't have to strip it and start from zero.

Another sign that the new Cardinal products are either catalyzed or a closed polymer (alkyd). The back at least will need striped back and done over, those witness lines will never disappear. Moreover I would be concerned about long term viability of the coating, this is a recipe for a de-lamination failure down the road.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Argh! Thanks for the thoughts, guys. Live and learn!

With the products I use, the cat versions of the vinyl sealer are single coat only products. That includes a low voc version which can be used either as a cat or non cat depending on the top coat chosen. No second coat required or permitted. The nitro version can be recoated at any time with no sanding. So this shows how different products from different manufactures can be.

In fact my manufacturer discourages the use of vinyl under their nitro due to possible delamitation caused by the lack of burn on that Todd mentions. Again this is why it's important to work within one system from one manufacturer and to be familiar with how it operates.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Good info for me since I am planning to try cardinal nitro on the next build. Love to hear cardinals response also.

Keep it coming !!!

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Joe Beaver
Maker of Sawdust

Alright guys, I did the dirty deed. It's stripped and cleaned. The fill is still fine, but I wiped a wash of Z-Poxy just to even out anything I didn't see.

I'm going to follow Todd's lead here and just lay down a 3-4 mil coat of sealer. I want to get my hands on a mil gauge just to make sure.

It sounds like I should scuff the Z-Poxy before spraying the sealer, and clearly scuff the sealer before starting the top coats.

by the way James, that is nice looking wood!!! Is it Imbuia?

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Joe Beaver
Maker of Sawdust

Thanks, Joe. It's a pretty sweet set of Tiger Myrtle with a bit of curl. I'll post some pictures when it's done.

I heard back from Mac on Tuesday. He says:



I just came in from spraying a nice heavy coat (one pass over the entire guitar, then another). I dialed my air pressure down to about 10 psi, and got a much better result. The gun had been set at 18 (Iwata's recommendation), but it looks like that was just too much here. I'll scuff tomorrow and shoot three or four similarly heavy coats of lacquer.