water vs oil based polyurethane

[John C Bush]

I am ready to finish a large walnut slab L-shaped desk with waterfall ends and would like to use a water based poly to finish due to ease of use , clean up, and multiple coat application time. I repaired/sealed several defects and cracks with epoxy--smaller splits with CA--and am wondering if water based will bond/seal to the epoxy. Also, does the water raise the grain? I generally use Daly's Satinthane and it has always covered epoxy and CA well. I usually hand rub Daly's profin teak oil in up to 400 wet /dry paper to fill in the grain(sanding sealer??), then apply Satinthane. Great finish but lots of work. Newer versions of the waterbased stuff are advertised as very durable-even for a desk, and the ease of use mitigates a little less durability. Not sure how much difference there is with color and grain highlighting. My research indicated the water based is a lighter finish not sure if an issue with walnut.

So, question is--what type of finish would you recommend and any brand suggestions. Thanks, JCB

[Wayne Lomman]

Water-borne is okay if it is a good one. I always use 2 pack polyurethane. It's durable, water clear and I prefer to do a job once. Cheers

[John C Bush]

Is 2 pack a mixed catalyzed system. I am familiar with a 12 pack--cold ones!

[Andy Giddings]

John, you might want to move this to the Finishing forum to get more answers.

Water borne finishes often raise the grain on the first coat. The ones I use need to be scuff sanded between each coat which means this isn't an issue for the smoothness of the finish. In terms of color, most of the WB are clear IME with EnduroVar being the exception (has a slight amber). In order to get the grain pop that you normally achieve with an oil based finish, shellac as the first coat helps - without this WB can be bland compared to oil. In terms of covering epoxy, I would think it would be ok as long as the surface is scuffed to provide a key, but I would check with the manufacturer to be sure. In the General Finishes brand, EnduroVar or EnduroPoly are both at the top end of the durability range

[John Lankers]

I think it all depends on the look you're after. I usually spray a 1 1/2# cut dewaxed shellac as a sealer and then the water based poly. I use an Earlex 5500 and spray Varathane Diamond Woodfinish thinned with 5% Zinsser Latex extender - no water - and get great results. Grain raising has never been an issue for me.
Others probably take a different approach but this is what works for me. In my experience several thin coats yield the best results but because it dries so quick it can easily be finished in an afternoon.
Whatever you do, try it out on some scrap first.

[Rich Engelhardt]

MinWax makes an oil modified water based one that I used on a kitchen last year.
I liked it.
Unlike most waterborne poly, this one didn't show the brush marks (too badly).

I got it at Lowes.

[Larry Edgerton]

I have been using Gemini Finishes Titanium, love the way it works, builds well, no problem with West System as I sometimes do a base coat of 207. Hard to find here, I have to order.

[Wayne Lomman]

Ever heard the song "May Your Fridge Be Full of Coldies"? It's a good one to play when wishing someone well, birthday, wedding, etc. It's by Greg Champion by the way. And yes I do mean a two part base and curing agent product. Cheers

[Curt Harms]

John, you might want to move this to the Finishing forum to get more answers.

Water borne finishes often raise the grain on the first coat. The ones I use need to be scuff sanded between each coat which means this isn't an issue for the smoothness of the finish. In terms of color, most of the WB are clear IME with EnduroVar being the exception (has a slight amber). In order to get the grain pop that you normally achieve with an oil based finish, shellac as the first coat helps - without this WB can be bland compared to oil. In terms of covering epoxy, I would think it would be ok as long as the surface is scuffed to provide a key, but I would check with the manufacturer to be sure. In the General Finishes brand, EnduroVar or EnduroPoly are both at the top end of the durability range

The color or lack of it in clear water based finishes is easy to address. Transtint works beautifully with WB Poly or shellac. You can have about any color tint you can imagine. Durability is something I have no experience with.

[Chris Hachet]

I usually hit the wood with a very thin coat or dewaxed shellac, highly thinned oil based poly, Watco oil or similar, and then finish with Water based finish after the oil based stuff has dried a good 3-4 days.

I find putting a quick coat of clear on pieces before I glue them up actually helps avoid glue spots. I can lightly sand a piece with 400 grit or something similar before the first coat of waterbourne and I am usually good. this also will put the light Amer color into the wood if you want it there-If not, dewaxed shellac will dry clear.

Regards,

Chris