New tricks: Water based

[Cliff Rohrabacher]

Issue: Can I apply the water based finishes over an Alkyd urethane that is well cured (months old) and sanded?

I need a fast dry finish real fast.
In my old home it's near impossible to get a dist free environment. Water or alcohol based finishes may help solve for that.
I rather suspect that dust was what drove the ancient finishers to invent French Polish. In theory you can apply FP anywhere under nearly any conditions that might be typical of an old school wood shop. But it's so much work.

Gotta learn the new finishes. The Chem engineers of water based finishes have had plenty of time to get it right. Fuhr 255 has been around for more than a decade. Even MinWax (not that I have much trust in them) have a couple of water based finishes.

So I ask:
First issue: Can I apply the water based finishes over an Alkyd urethane that is well cured (months old) and sanded?

[Prashun Patel]

It's probably fine, but if it were me, I'd put down a 'primer' of dewaxed shellac first. Then you'll be certain of no probs. Zinsser sells the aerosol cans for like $5 at BORG. They're blonde, but dewaxed.

I was like you. I invested in the standard cheap hvlp (cycle between Woodcraft, HF, and Rockler) and you can get it under $80 delivered. It's a pro at spraying WB finishes - at least Target USL, and shellac.

I am very glad I invested in a spray unit. Savings in time and sweat equity paid for the unit on the 1st project...

[David Christopher]

Can the USL be buffed like the solvent based laquer ?

[Rob Cunningham]

Can the USL be buffed like the solvent based laquer ?

Yes it can be buffed but you need to let it cure for at least 100 hours before starting the rub out process.

[Cliff Rohrabacher]

Can the USL be buffed like the solvent based laquer ?

What is USL?

[Prashun Patel]

Ultima Spray Lacquer. It's from TargetCoatings. Lots of people round here like to spray it. I think the name might be obsolete now, though. It might be found under Oxford or Emtech.

[Jim Becker]

Issue: Can I apply the water based finishes over an Alkyd urethane that is well cured (months old) and sanded?

Yes, you can.
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Many of us would likely apply a barrier coat of dewaxed shellac, as was previously mentioned, just to be sure there are no incompatibilities. It's a small extra step, but not substantially painful to do!

I'm also a fan of Target Coatings finishes. They only do water bornes--as was the case with Fuhr. The USL (Ultima Spray Lacquer) that was mentioned is a very good finish that has some of the desirable characteristics of solvent based lacquers (such as burn-in) without the danger inherent in using solvent based lacquers. USL is the successor to their previous PSL (Premium Spray Lacquer) and now looks to be replaced by Target's Emtech 6000 production lacquer. BTW, Target is based in NJ so they are a local business for you to support, too, Clifford.

[Howard Acheson]

>> Can I apply the water based finishes over an Alkyd urethane that is well cured (months old) and sanded?

Certainly, just scuff sand it evenly with 220 paper. Apply at least two coats sanding between the first and second with 320 paper. No need for a barrier coat.