OK Sonny, remember what you paid for this next several paragraphs in case i t doesn't work for you!
First, the BLO will be in the bark and it won't come out. Nothing will get it out. Sorry to say it, but there it is, sir. You can seal it and encap sulate it, but the oil will destabilize anything you put on top of it, incl uding shellac IF there is enough oil left in the bark.
Second, on the surface of the trestle, you need to scrub off the oil. You won't be able to sand it off, and probably can't out wait it, either. With drying wood underneath it would be difficult to guess how long the oil will stay gummy. Back when I was doing a lot of finishing/refinishing (careful ... remember what you are paying for this) I had been told by another finis her that green wood had enough sap in it to mix with BLO and keep it from E VER hardening. Ouch! That could be folklore or just his experience, but t he strangest things can foul a finish.
What to do? You already know.
Since you do, I will give you my top secret, "hasn't failed ME yet" way of handling the removal of a fouled finish, which is what you have at this poi nt. I will skip the unnecessary discussions of why some things work and ot hers don't and just tell you my method.
Since you aren't doing a ton of removal, check this out as a good quality, reliable stripper:
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144685
Apply a heavy coat with an old paint brush. Now we get to my method.
Using the thin painter's plastic, cover the treated surfaces with the plast ic and put plastic right into the stripper. Mash down the edges in the goo ey stripper so air can't get in. On uneven surfaces, I tape the plastic do wn. Go drink a glass of tea while waiting for twenty minutes. Don't get a nxious and pull up the plastic, wait for it.
Pull the very edge/side that you first applied the stripper to up, just a s mall area of about 4"x4", or maybe a little bigger. This is better if you can do it on an area out of sight as it will be your testing media. Take o ne of those .99 cent throw away plastic putty knives (NO METAL)and gently s crape off the goo. Look clean? Put some lacquer thinner on a rag and wash your test area to remove all the goo if it does. Wait a minute until dry, then give it a final wash with lacquer thinner. It should be cool and dry . If it isn't, then put more stripper on it and wait another 10 minutes, t hen try again.
You shouldn't have to wait more than 20 minutes for simple oil finish as it has no engineered, plasticized resins in it, just flax seed resins and a l ight metallic dryer. It would be impossible for me to think you had to do this next step of removal more than once.
So now you are happy with the stripper's work and ready to go. Here's the big finish. Get a couple of pounds of table saw sawdust, NOT PLYWOOD OR MD F, OSB, or any other manufactured product. Not planer shavings, not router swarf, or wood from the drill press. Table saw dust only, please. Don't use colored shavings like walnut, bubinga, wenge, or anything like that. M y preference is hard maple or hard yellow pine. This will become your scru bbing medium. Remember when I warned you about the oil in the tubules of t he wood? We are now going to fix that.
Take a good, stiff plastic bristled scrub brush in one hand, and pull back a small section of your plastic that is covering the trestle. Work quickly . Broadcast a small handful of sawdust onto the stripper goo and scrub the wood in a circular motion. Do NOT scrub along the grain as a good hard br ush with sharp medium will cut into the wood, leaving a "raised" grain. Sc rub well, and when you are finishing the area, apply enough of your sawdust to dry out the stripper until it forms little balls and pieces of drying s tripper, BLO and sawdust. Your sawdust medium will not only multiply your scrubbing efforts, but it will reach into those tubules and pull out the oi l as it dries. A brush alone will skate over the tubules unless you use a v ery fine brush, but it would be too fine to be suitable for scrubbing.
By the way, you have now solved what to do with the removed goo problem whi le using this method. I do this over a cheap plastic tarp or whatever else I have on hand and simply wait for the sawdust to dry before I clean it up . This is a wonderful method to use when stripping off a ton of finish tha t requires two or three passes of stripper and generates a lot of gooey fin ish.
Back to the project Uncover another small area, and repeat this until you a re at the end. When you arrive at the end of the trestle, you should have little balls of dried/drying sawdust on the trestle as well as on the floor around it. Wipe off the trestle, then brush with a medium bristle cleanin g brush with the grain to make sure you removed all the solid residue. Don 't leave the tiniest speck. Go have some more tea and come back to this in 30 minutes. The little balls should be dry, and the trestle top should be fairly and dry, but not real clean. Sweep up the little dried balls of sa wdust (sweet! No gooey mess!) and dispose of them.
Juglas woods can and often will leave color trails when cleaning under regu lar circumstances, but cleaning off remaining resins and stripping chemical s will almost guarantee it. Go buy the cheapest lacquer thinner you can ge t (like Sunnyvale) and soak a on old T shirt with it an wash down (not a ge ntle rub with a wet rag, wash it) down all at once. Be careful not to have dry spots as they will leave witness lines of color trails that will look like puddles. Wash it and keep all surfaces moist and wet until you are fin ished, then let it all dry together at the same time.
You should be finished after it dries, ready to sally forth into another fi nishing adventure!
It goes without saying that you need to do this in open air, wear a mask fo r these chemicals, and certainly nitrile or real rubber gloves for protecti on. Keep soap and a lot of water by (the hose, perhaps?) when working with the stripper as the Klean Strip is really aggressive on skin.
Good luck, buddy. If you get goofed up somewhere, post back here. Be patie nt if you are waiting for a reply from me.
Robert