HELP!!! BLO got in my dog holes and is sabotaging my hold fasts!

[chris carter]

A few days ago I re-flattened my work bench. I gave the newly exposed surface a coat of BLO. I didn't realize that when I first built the bench I applied BLO before I drilled the dog holes. So I think a tiny amount got into the lip of each hole. Today I tried to knock in a holdfast and they just would not hold AT ALL. Previously they held like a hungry lion locked onto a wounded giraffe - even with just hand pressure. Now, absolutely NO GRIP whatsoever - even whacking hard with a mallet. What do I do? Is this fixable? Did I just completely screw myself???

[Mark Gibney]

I'd get an old toothbrush, a small container of acetone, and scrub the walls of the dog holes.

When you've finished I'd get 100 grit sandpaper and rub the walls of the holes sideways a little.

[Don Dorn]

Interesting - just built a new bench and used 3/4" holes. I find them pretty tight and not nearly as easy to use as my old bench, especially in summer humidity. On the old one, I took the leap and reamed all the dog holes to 13/16". After that, I never had any problem getting anything in or out but wasn't "sloppy". I'm considering that again, but once you do it, you can't go backwards so I'm a bit hesitant. In the old bench, the BLO I put on once in a while was never an issue.

[Tom M King]

How about a round wire brush, found in the Plumbing section of box stores, for cleaning copper fittings to prepare for solder. If by hand is too slow, cut the handle off, and chuck it in a drill.

edited to add: Only spin it clockwise. If you go the opposite way that the bristles lay, or go back and forth with it, the bristles will go all haywire, and maybe dig the hole out more than you want, not to mention ruining the brush.

[Bob Glenn]

Give it a few days or weeks and it should resolve itself.

[Stew Denton]

Chris,

I think the idea of scrubbing the dog holes with an old tooth brush and solvent has some promise.

However, I think paint thinner would be a better solvent than acetone. Paint thinner, not mineral spirits, mineral spirit will be slower to evaporate. Toluene has better solvency properties than either the paint thinner or acetone, but is considered pretty bad for you. If your bench is in a location where the toluene can dry and the fumes not be a problem, it will be a better solvent for BLO. I am not sure how well the cured BLO can be removed by solvent, but again, the toluene has the best solvency properties.

Sew

[Charles Guest]

How much material did you remove from the benchtop when flattening it? The linseed oil in the holes shouldn't cause what you're experiencing. At any rate, wait until it's cured to see what happens then.

[chris carter]

I didn't take off much at all; probably a 32nd as it was relatively flat (flat enough to work on). I was about to install a mortised bench stop I got from LV and figured I should take care of any flattening first so I could keep the recess as minimal as possible and reduce the need to adjust it down the road after a flattening.

I did try scrubbing the holes with mineral spirits and a toothbrush and then wiping with paper towels yesterday. But I'm now thinking that really I just need to take a woodworking vacation and let it cure and see what happens. If it's still like this in 2 weeks, then I'll tackle it then with some alternate plan of action.

[Jeff Ranck]

can you make your holdfasts rougher so they are grippier? Maybe attack the problem from a different angle.

[Jim Koepke]

Did any of the residual BLO get on the holdfast? This could be part of the problem.

One of my first thoughts was to fill the dog holes with a fine sand. Hold a can underneath to catch it when it comes out the bottom. Not sure this would add to the holding ability or not. You could try it on one hole as an experiment.

jtk

[Charles Guest]

Stop the holes with glazing putty and fill them with turpentine. Let it evaporate or leak out, whichever comes first. Then wait several days before trying to use the holdfast.

[chris carter]

Well, this is interesting. I have two rows of dog holes and they are different depths. The front row is 2” thick and it runs above one of the pipes from my twin-screw pipe clamp vice which doubles as a tail vice; it is basically only receives dogs. The other row about 6” off the back of the bench are spaced far apart and are where I use my holdfasts and only the occasional bench dog. This row is 4 ½” thick. The bench is made from construction lumber (SPF). I tried a holdfast in one of the 2” thick holes and it held fine. So what I’m thinking is that the holes that are 4.5” thick worked perfectly fine when there was ZERO oil, but now they are just out of tolerance because of the BLO. I knew that 4.5” was at the upper limit, but I wasn’t concerned because I could counter bore them if necessary. It seems it might become necessary now. It’s irreversible, so I will try and wait another week or as long as I can to see if the problem solves itself first before I try and drill the bottoms bigger. It doesn’t sound like it would be fun either – trying to drill a hole upsidedown in a smaller hole that already exists is not my idea of a good time. If it gets to that point I’ll be seeking advice on how to keep the drill (power/spade bit) steady when there’s no center to anchor it down.

In the meantime, I’ll cross my fingers that a couple weeks of curing will do the trick. It seems to me that with all the projects I’ve done, at SOME point I must have gotten a more than a few drops on a hole before and maybe it was just that I didn’t wind up needing that hole for a couple weeks and so never noticed an issue. That’s my thought anyway.

[William Fretwell]

I don't know if you have a heat seal air gun, it gets much hotter than a hair dryer. Direct it down the holes to speed up adsorbtion into the wood. You could try increasing the holdfast spring pressure and painting the holdfast with rubber contact cement and let it dry to increase friction.

[John Kananis]

Which holdfasts are you using? 4.5" is a lot of bench-hole. The holdfasts may have just been holding before this incident; what about taller stock though? I would consider counter-boring (just like you were contemplating).

[chris carter]

Which holdfasts are you using? 4.5" is a lot of bench-hole. The holdfasts may have just been holding before this incident; what about taller stock though? I would consider counter-boring (just like you were contemplating).

I'm using the Gramcery ones, lightly sanded with 100 grit. I think that may be what's happening. I think perhaps when the holes had no treatment at all, the 4.5 deep holes were never an issue; impossible to pull out by hand and typically took a good solid couple of whacks with a mallet to release them. I suspect I may need to drill out an inch from the bottom. But I don't NEED the holes for at least a few more days so I'm going to hold out as long as I can before I go down that path and see if some curing time will take care of things.

[Mike Brady]

I never had any success with that brand of holdfast, no matter what I did to them. The steel rod they are made from is just not suited for some bench designs / materials. If you have roughened them and still have no joy, then I would suggest you look to a holdfast made of forged or cast iron. I would also be wary of altering your bench in any irreversible way. Now I will seek cover from the return fire........

[John Kananis]

Consider making some divets with a nail-set to the contact points of the holdfast - should work much better than sand paper.

[Warren West]

I can't believe the BLO is the culprit here. Following along with interest.

[chris carter]

I can't believe the BLO is the culprit here. Following along with interest.

I know, that's what I'm thinking! But that's the only thing that has changed. Absolutely nothing else changed other than skimming off maybe 1/32nd of surface. At someone's suggestion in the thread I cleaned off my holdfasts in case there was BLO on them and they still didn't hold. The project I'm doing right now (a jointer plane build) I don't think I'll really need the holdfasts so that gives me some time to see if curing will work. I will be sure to post the results, whatever those results might be.

[John C Cox]

How about reaming the hole back out with whatever drill or reamer you used originally?

There's a chance the solvent/oil swelled the holes a bit and they are tighter than they were originally...

[Simon MacGowen]

I know, that's what I'm thinking! But that's the only thing that has changed. Absolutely nothing else changed other than skimming off maybe 1/32nd of surface. At someone's suggestion in the thread I cleaned off my holdfasts in case there was BLO on them and they still didn't hold. The project I'm doing right now (a jointer plane build) I don't think I'll really need the holdfasts so that gives me some time to see if curing will work. I will be sure to post the results, whatever those results might be.

If you have ruled out all other factors (change in humidity, change in the holdfast etc), the BLO has to be the culprit.

And if you have tried all other solutions in vain, you may try this: Glue a solid hardwood dowel (a hair larger if possible) into one of the holes and let it cure (18 hours or 24). Then redrill that sample hole and try the holdfast. If it works, plug all the rest and drill. That should not be a lot of work if you have a row of two dog holes.

Another alternative is to glue a board 1/2" to 3/4" thick to the underside of the bench and use the existing holes as a guide to drill new holes. Again, try this out with a sample hole first.

Waiting for the BLO to dry? That is too passive for me, plus there is no guarantee that once it dries (it could take months), your problem is solved.

Simon

[Charles Guest]

If you have ruled out all other factors (change in humidity, change in the holdfast etc), the BLO has to be the culprit.

And if you have tried all other solutions in vain, you may try this: Glue a solid hardwood dowel (a hair larger if possible) into one of the holes and let it cure (18 hours or 24). Then redrill that sample hole and try the holdfast. If it works, plug all the rest and drill. That should not be a lot of work if you have a row of two dog holes.

Another alternative is to glue a board 1/2" to 3/4" thick to the underside of the bench and use the existing holes as a guide to drill new holes. Again, try this out with a sample hole first.

Waiting for the BLO to dry? That is too passive for me, plus there is no guarantee that once it dries (it could take months), your problem is solved.

Simon

The BLO in the hole might have something to say about the glue curing, no?

[Simon MacGowen]

The BLO in the hole might have something to say about the glue curing, no?

According to the OP, the holes are not like flooded with oil, and it is more likely part of each hole is contaminated only, leaving enough surface area for the glue. I suggest a test with one of the holes and that will reveal if the dowel method will work or not. Same for gluing a board to the underside, using a test piece first.

Simon

[Charles Guest]

According to the OP, the holes are not like flooded with oil, and it is more likely part of each hole is contaminated only, leaving enough surface area for the glue. I suggest a test with one of the holes and that will reveal if the dowel method will work or not. Same for gluing a board to the underside, using a test piece first.

Simon

I'd still stop the holes and flood them with solvent and let it evaporate out. Use some other means of work holding in the meantime, like a week may two, tops.

[Simon MacGowen]

I'd still stop the holes and flood them with solvent and let it evaporate out. Use some other means of work holding in the meantime, like a week may two, tops.

I wouldn't disagree with you or to any other solutions people may have suggested, because I offered my suggestions with this rider: "And if you have tried all other solutions in vain..."

Simon

[Stew Denton]

Chris,

I tend to go with the least aggressive simplest thing first. This is my approach on most things.

One problem with the BLO is that it cures, polymerzing to where the material becomes chemically bonded together. If it gets to that point, it will not dissolve in a solvent. It may soften, but won't dissolve and leach out.

I think the first thing I would try after waiting a couple of weeks, as you mentioned, is light sanding. If waiting does not help, I would wrap a dowel with something like 100 grit sandpaper and lightly sand the inside of the holes near the top. I would just remove a little, and only try one hole first.

Stew

[chris carter]

Update.

Well, just now I decided to wait no longer and counter bore the underside of the holes. I figured I should only need to take them down just a tiny bit, like a half inch. Nope. I ultimately had to take them down to 2.5 inches to get them to hold solidly (testing; not real-world scenario... which might be different). Still, I have one hole that doesn't seem to want to cooperate and will only hold the fast in certain directions. Bear in mind, when these holes were 4.5" thick they had ZERO problems; I could just use hand pressure and it was enough to be able to lift the bench. At this point I can go no further. Given that the bench is SPF construction lumber, I'm afraid at the depth they are I will likely wear them out fairly quickly. I think I have usable holes for upcoming projects... we'll see how they do.

The good news is worst case scenario, my bench is designed in such a way that I could actually replace just the top without having to really disturb any other part of the bench. So that may be in my future if after a month I'm having problems. I can just build a new top exactly like how this one WAS.

I might add, I did not get much BLO in the holes. There were no "drips" into the holes. I just wiped down the whole surface twice with a rag.

So I'm kinda bummed right now. But the good news is I built a jointer plane, so I'll post about that to cheer me up.