>I have been experimenting with this technique of grain popping using linseed or tung oil. For those that have used this approach, what do you use for a top coat that sticks? Have you worried about adhesion of the top coat?
There is inadequate adhesion with this treatment when the top coat is : Sherwin Williams conversion varnish, butyrate lacquer, or polyurethane. Shellac did adhere properly. I suppose an old fashioned varnish would work, but I don't know who sells such a thing now days.
Skip the oil! I have never used conversion varnish, but shellac and poly usually pops the grain nicely without oil underneath. I would use shellac to seal the oil before using other finishes on top. It might be worthwhile to do a couple of samples with and without oil to see the difference. When trying new finishes or techniques it is worth the time to try it on scrap.
Do not use BLO or tung oil if you are going to top coat with a film finish. While these oils may produce the look you are after, they are slow to dry. It is best to use a product that has commercial dryers in it to ensure that the oil is cured prior to top coating. I like natural Watco for this purpose because it drys consistently. The process I use involves applying one coat of Watco, waiting a full three days, and then spraying with a precatylized lacquer. I am currently using Campbell's MagnaLac. The key is to wait long enough to let the oil dry. Adhesion has not been a problem. In this process the oil is basically a stain. I find that I do this mostly with cherry, where the freshly prepared wood looks to pink with a clear lacquer. Most of the time clear lacquer highlights grain very well, and I do not have three days to wait to shoot a topcoat.
>I have been using a blend: 1/3 min spirits or turp, 1/3 BLO, 1/3 polyureathane. Wipe on, come back 2-3 hours later, wipe off any residue with a cotton cloth. Next day, rub out w/ OOOO steel wool, and repeat above. Continue until finish is where you want it. I put about twenty coats on a mesquite coffee table and end table set. Doesn't shine like straight poly, but more than BLO or tung oil. I did this about a year ago and haven't had any bleed from the BLO.
>While I have picked up many good tips on WoodCentral, "grain popping" with oil is definitly not one of them. Ideed, I would add this procedure to the Woodworking Myths file. When experimenting I test for adhesion; I expect some people don't. Given what I saw with the linseed oil and tung oil I conclude that this approach is too risky. How would one know that a wiped film of oil had adequately dried(cured) short of observing adhesion of the top coats?
>For mahogany, I use Kusmi buttons in a 1 1/2 lb cut, half amber, half red brown (any shellac will work, but I like the salmony and amber mixture), plane/scrape/burnish to desired fineness. Even if you're listening to Limbaugh, liberally pad on a coating of shellac. Let dry (not really dried and certainly not cured but at least not tacky) a few minutes, repeat. You'll end up with a scratchy looking and feeling surface. This coating will allow controlled penetration of your oil, which you wipe on now. The shellac also will combine with the oil to fill pores. Give it a couple minutes to soak in, then wipe off with paper towels.
Next, I like to buff with tripoli on a 10" unstitched and unstructured flannel wheel until I just begin to smell the oil cooking but before it gets sticky or tacky. At this point you can either add more shellac, let dry, sand lightly with 320 grit and a little oil until a paste forms, which you rub into the grain. It will be very smooth but gummy. Just before it dries (depends on the oil used, humidity, etc., start removing with a lint-free rag or paper towel pad, VERY LIGHTLY, until your surface begins to feel slick and loses its muddy cloudiness. If you prefer an even smoother feel, repeat one wet sanding with 600 grit. I like to finish by dry rubbing with the 3M blue 1200 and pink 4000 grits. Now, if you have it, buff with tripoli on unsticthed muslin until it warm and smells somewhat burnt. The tripoli residue also works into the grain but looks just fine on mahogany, cherry, walnut, and even oak. Wipe down and wax, if desired (most tripoli bars have a bit of wax in them).
Even faster (and better, IMO), is to use Waterlox instead of plain oil, skipping the tripoli and flannel buffing. This is what I call my 'emergency' finish. It pops the grain at least as nicely, dries harder and leaves a slightly brighter finish. It responds superbly to buffing wheels and gets hard in no time, and can be immediately handled.
I had occassion to use it only last Friday. I'd built two 22"x22"x3" mahogany cases for Etruscan/Egyptian/Hellenic chains for our local Venice Arts Center exhibition, but it just didn't look right to mix the 22k gold Etruscan with silver, so the afternoon just before setup time, I made up another smaller 12" box to display it seperatly. A few passes with a 2/8 Greco-Roman ovolo moulder (it's just slightly elliptical), an hour's worth of rubbing and buffing, and it looked just like the other two. Thank goodness for hide glue, shellac, and tung oil based Waterlox. Great stuff. The chatoyance of red to gold was pretty eye-catching but admittedly the gold got most of the attention.
Anyway, I also like this on curly cherry, walnut (esp. air-dried), and red oak (which it darkens a bit). I use other finishes on maples. May not be quite what you had in mind, Bill, but works for me.
Credit must be given to Frid's Fast Fine Finish for convincing me you don't have to wait days for oil to dry.
>Rebecca Wittman discussed this in 'Brightwork', and we used to do a coat or two of oil on both mahogany and teak with real marine varnish like Epiphanes or Interlux. Sanding the stuff into the wood provided a grain filler which cut down on the number of coats needed to level for a gloss finish (usually 8-10 coats from bare wood using a standard marine varnish thinned 50/50 for the first two coats)
I really like the Interlux product, now known as 'Original' - not for sale in CA, so you KNOW it's the good stuff...
Behlen's Rock Hard and McCloskey Heirloom are real live short-oil varnishes which will adhere to surfaces treated with a curing oil - I've used both on interior stuff, and strongly prefer the Rock Hard.
Personally, I never thought it really added much, provided the top coat was real shellac, varnish or lacquer.
>I don't get around much, but this thread is the first time I have eve heard of BLO "popping" the figure as a myth. I would appreciate from more experience finishers than me to elucidate a little.
I'm currently working on a maple office suite and have been pretty successful with this combo: BLO followed by Olympic brand gel stain overlaid with Minwax wipe-on poly. I've had no adhesion problems at all. Granted, I haven't tried the combination without the BLO, but the figure is popping nicely.
