# sanding Boiled Linseed Oil? Need help!!



## ScStowaway (Sep 11, 2012)

So Im refinishing an old desk (you can view my thread on that), I finally removed the old finish (top). I decided to use some BLO over the mahogany top, and it looks wonderful thus far. My plan was to use General Finishes High Performance water based as a top coat. here in CA we dont have access to lacquer or oil poly. I was told I could apply the top coat straight over the BLO if cured completely, give it a week or two... So I gave it 4 weeks, just did a little section in the corner, and nope, didnt work. So I freak out a bit, naturally. I called General Finishes, a nice man said itd be ok, quit crying like a girl and just use some stripper, then seal it with dewaxed shellac and proceed. After drying my eyes, I asked if stripper would damage the BLO, he said no. So I apply some stripper, and it appears it has removed some of the BLO as well. Which is fine, I dont mind reapplying. My concern is that I feel Im gonna need to sand this area a bit, stripper residue, plastic putty knife marks ect. Is this gonna be a problem?? Whats my best bet to get this little section to blend with the rest of the surface?? Im looking for helpful replies only please, save your "noob mistake" comments. Normally I welcome any criticism, but for now time is of the essence. And plus, Im well aware of my noobness. Please and thank you!


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## Steve Neul (Sep 2, 2011)

I think it was a mistake to use stripper on the desk. You just needed to dry the linseed oil, not remove it. If you rinsed the stripper off with water you probably raised the grain and will need a little fine sanding. Anyway from where you if the wood is smooth put another coat of linseed oil on and wait about 5 minutes and wipe off the excess and let it dry. It's winter now so it will take longer than you think. After a day or two if it still feels wet put a heater in the room but not close to the desk to help it dry. When its dry enough you can't rub some off with a clean cloth lightly sand the surface with 220 grit paper. If the linseed oil is gumming up on the sandpaper it's not dry enough yet. All you are trying to do by sanding it is make it smooth. If it is already smooth you may not need much sanding. Then it is ready to put the water based polyurethane on it. The dewaxed shellac is not necessary with linseed oil on it. It would have been good if you were going from raw wood to water based polyurethane to prevent it from raising the grain.


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## ScStowaway (Sep 11, 2012)

Steve, Well I wasnt trying to remove the linseed oil, i was trying to remove the GF HP because it was clear right away it wasnt adhering properly. Although in stripping the poly, some of the linseed oil came up with it, but I just applied a little more to that area after a real light sanding and it looks good. Not sure I follow you regarding the shellac being unnecessary... If after 4+ weeks to dry and cure just one coat, it still wasnt happening, not sure when it would, or if id wanna wait that one out. I live in southern Ca, so hasnt really been all that cold the majority of the time, it was dry to the touch after just a couple days. And you were right about the grain raising. Very little, just a bit of sanding with 320, already gone. Thank you very much for your quick reply, much appreciated!


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## cabinetman (Jul 5, 2007)

ScStowaway said:


> My plan was to use General Finishes High Performance water based as a top coat. here in CA we dont have access to lacquer or oil poly. I was told I could apply the top coat straight over the BLO if cured completely, give it a week or two... So I gave it 4 weeks, just did a little section in the corner, and nope, didnt work.


What was the result? What did the WB poly do or not do specifically? How did you apply it?









 







.


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## Fred Hargis (Apr 28, 2012)

Sanding that will not be a problem, I often fill the grain by "slurry sanding BLO into it (this is with wet/dry SC paper). The shellac will get you into business a little quicker. Give the BLO a little time to cure, a day or 2. Apply a coat of shellac, sand smooth and then the GF top coat. Some cautions: shellac is difficult to use the first few times, so if you haven't used it consider reading a little about padding it on; and it may well provide a color shift that you don't like. Test it out, and be sure any shellac you use is dewaxed. Waxy shellac can have some adhesion problems with water borne and urethane resin finishes.


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## Steve Neul (Sep 2, 2011)

ScStowaway said:


> Steve, Well I wasnt trying to remove the linseed oil, i was trying to remove the GF HP because it was clear right away it wasnt adhering properly. Although in stripping the poly, some of the linseed oil came up with it, but I just applied a little more to that area after a real light sanding and it looks good. Not sure I follow you regarding the shellac being unnecessary... If after 4+ weeks to dry and cure just one coat, it still wasnt happening, not sure when it would, or if id wanna wait that one out. I live in southern Ca, so hasnt really been all that cold the majority of the time, it was dry to the touch after just a couple days. And you were right about the grain raising. Very little, just a bit of sanding with 320, already gone. Thank you very much for your quick reply, much appreciated!


 I'm sorry. I guess I misread your post. Yes the stripper will cut what linseed oil that is on the surface and another thin coat will bring it back. It's hard to say but sometimes different products react differently to each other. Perhaps you would have had different results with a different brand of water based polyurethane. Obviously there was something in the linseed oil the General Finishs poly didn't like. Normally you can put water based poly directly over dried linseed oil. Maybe to be on the safe side you should do like Fred said and put a coat of dewaxed shellac on as a barrier coat before going with another water based poly. I wouldn't change brands of finishes at this point. Every different finish has its quirks and when you work it out stick with it. Every time you change brands you have different problems to work out.


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## ScStowaway (Sep 11, 2012)

Cabinetman and Steve, havent yet got there. I finally got the section I destroyed back to into shape. It was lookin pretty nasty there for a bit, the stripper pretty much removed ALL blo. But now, the only thing still visible (as far as the mistake) is in the right light at the right angle, there is a slight glossier section of an outline. Im assuming this is from me not applying the stripper far back enough, and thats just some of the wb poly that made it in. The blo under it is intact, so im wondering if rather than apply more stripper,(which boggles my mind that it doesnt just eat the wood), maybe just continue on, and once the poly is on the rest of the desk, over the de-waxed shellac of course, itll all look uniform again??

I love this website. Not once has one of my questions gone unanswered. You guys are the best, Thank you.


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## Fred Hargis (Apr 28, 2012)

Take a cloth and put a little MS on it, then wipe that over the area in question. Look at it carefully while it's wet...it will have the appearance of being finished and give you an idea of what it will look like. The MS shouldn't hurt anything if you put on just enough to get the surface wet.


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## Steve Neul (Sep 2, 2011)

What Fred suggested is not a bad idea to wipe the piece down with mineral spirits to see what it looks like. Once the mineral spirits is dried if the color is uniform you might put a small splotch of water based poly here and there to see how it does. I think since you stripped the excess blo off the surface you can just go ahead and finish it with the poly. I think the initial problem was there was too much blo on the surface that was not quite dry and it may be ok now. You mentioned you think some of the water based poly is not stripped so I'm a little apprehensive about putting Sealcoat over water based poly is why I think you might be better off not using it.


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## ScStowaway (Sep 11, 2012)

Fred, thats exactly what i did do, I love mineral spirits for that reason in itself! when i did that, it all looked dandy, even the outline (suspected leftover poly) vanished. 

Steve, the only issue with your suggestion, is that I DIDNT strip away all the BLO, only in the small area that i applied the poly. And then in the are where I did strip, I added BLO to match it with the rest. So its got a 4 week handicap. and even then, 4 weeks wasnt enough to take the poly. But u raise a good point about the sealer over the poly... Ill test on scrap and report back with a full report.

Thanks guys, tbc...


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