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Larry Beyer
08-19-2005, 3:29 PM
Hello All.
Brand new, the first time on this forum..the entire site for that matter.

In about two weeks I will have completed a Black walnut aquarium stand.
For finishing I have looked on this and several other forums. I would like the cabinet to have a nice "deep" furniture look and yet not be damaged by water on the top and not require monthly/yearly maintenance.

I am looking for an affirmation of a system. Do you think the following "system" will do what I want?
Tung Oil (100%), Four or Five coats. [would BLO be better?]
Sand after first coat
On sucessive coats wet sand with application of oil (220 thru 400)
Wipe on Poly...three coats, over the dried oil.

If the abovementioned system will work, I have some questions as to how to do it. The reason I have questions is because upon reading about finishes on various forums there seems to be conflicting and even contrary information. Also, I have never used either Tung oil or wipe on poly.

Should the oil be applied full strength or cut with something for faster drying?
How long about to wait before wiping the oil off???
If I let each coat of oil dry for 24 hours after wipe off will that be sufficient?
If I let the final coat dry for a week before coating it with poly will that be sufficient?
I intend to make wipe on poly with 50/50 mineral spirits and polyurethane gloss coating; is there a better mix or proportion??
How long should/can I wait between coats of wipe on poly?
Is it necessary to sand between the coats of poly?

I know that with all the questions it seems like you have almost did the finishing work for me but I have never tried finishing a cabinet before so would feel more assured by some input from people with experience.

Thanx in advance for your help.

larry beyer

Jim Becker
08-19-2005, 3:46 PM
Since you are going to top coat, use the BLO...same basic look as the Tung Oil at a fraction of the cost and a much, much shorter cure time. With the Tung Oil, it will be months before you can top coat with the varnish. The wipe-on varnish is just fine, although you are realistically looking at many more coats than 3 if you want to build a finish. You do need to scuff between coats if you use polyurethane varnish if you let it cure for more than an hour or so. Poly hates to stick even to itself...

Howard Acheson
08-21-2005, 4:47 PM
Let me add to Jim's response.

Using tung oil or boiled linseed oil will have pretty much the same affect. It colors the wood causing the grain to become more pronounced (pop). One coat is all you need. BLO will cure much faster letting you get on with your next finishing steps.

The appropriate finish, IMO and I am not a fan of poly, is a oil based polyurethane varnish. Use a interior rated finish as it will cure harder and be more durable than an exterior product. You can thin the varnish you buy 50/50 with mineral spirits to make a wiping varnish. Wipe it on with a cotton rag or a non-embossed paper towel.

Here is something that should help. A friend of mine put it together years ago and it has worked well for many.

QUOTE

There are a number of suggested application regimens that are totally subjective. The number of coats in a given day, the % of cut on various coats, which coat to sand after, when to use the blade and a whole host of other practices are all minor differences between finishers. There are some things that I consider sacred when applying a wipe-on finish.

If you are making your own wipe-on the mix is scientific - thin. I suggest 50/50 with mineral spirits because it is easier to type than any other ratio and easy to remember.

The number of coats in a given day is not important. Important is to apply a wet coat with an applicator and merely get it on. Think of a 16 year old kid working as a busboy at Denny's you have sent over to wipe off a table. The applicator should be wet but not soaked. The applicator can be a paper towel, half a T-shirt sleeve or that one sock left after a load of washing. Then leave it alone. The surface should not be glossy or wet looking. If you have missed a spot, ignore it - you will get it on the next coat. If you try and fix a missed spot you will leave a mark in the finish.

Timing for a second coat involves the pinkie test. Touch the surface with your pinkie. If nothing comes off you are ready for another coat. If was tacky 5 minutes ago but not now, apply your next coat just as you applied the previous coat. Remember, you are wet wiping not flooding. After applying the second coat, let it fully dry for 48 hours. Using 320 paper and a sanding block ligthtly sand the surface flat. Now, begin applying more coats. Let each coat become tack free but do not sand between coats unless you have allowed more than 24 hours to elapse since the prior coat. The number of coats is not critical - there is no critical or right number to apply. For those who need a rule, four more coats on non-critical surfaces or six more coats on surfaces that will get abraded seems to work.

After your last coat has dried at least over night you will have boogers in the surface. You should not have marks in the surface because you ignored application flaws. You may have dust, lint and, if you live in Texas, bug legs. Use a utility knife blade at this point. Hold it between your thumb and forefinger, near the vertical, and gently scrape the surface. Gentle is the important word - no harder than you would scrape your face. If you start scraping aggressively you will leave small cut marks in the surface. After you have scraped to the baby butt stage gently abrade the surface with 320 dry paper or a gray ScotchBrite. Clean off the surface. Now, leave the area for two hours and change your clothes. Apply your last coat with a bit more care than the previous coats and walk away.

An anal person is going to have a tough time with this process. Missed spots have to be ignored. Wet wipe, don't flood. Scraping to babies butt smooth means scraping no harder than scraping a babies butt. Ignoring any of these will leave marks that are tough to get out. Getting these marks out requires some agressive sanding to flatten out the surface and starting over.

Jim Kull

END QUOTE

Finally, It works better to use a gloss varnish for all coats except the last. The flatteners in semi-gloss and satin tend to rapidly fall out of suspension when the finish is highly thinned. If you want a non-gloss finish, use it only on the final coat or two and be sure to stir the material frequently or you will end up with cloudy streaks.

For a surface that is going to get some abuse, be sure let it fully cure for 3-4 weeks. It takes that long for varnish to develope full adhesion and hardness.

*****
Oops, fixed the "304" to 3-4.

Chris Barton
08-21-2005, 6:30 PM
"304 weeks" of curing seems a little long:rolleyes:

Larry Beyer
08-22-2005, 8:40 PM
Thanx all for the info. I now know how to proceed.

304 typo wasnt a problem

Larry Beyer