Being a newbie, I'm not able to offer a solution, but am curious what your bench top is made from. Sounds like a softer species, so I'm curious if this is a common enough issue to be a good reason to consider a harder species in bench building (at least for the top).
Is that from holding skinny stock ? My Lie Nielsen holdfast ovalised one of the dog holes in my SYP bench top in no time, so I started putting a block between the palm and the piece I was holding to raise the holdfast head higher. I'm also using wooden pegs in the dog holes to oppose the movement of the work and using less pressure on the holdfast. I'm going to try holdfasts with either a deeper drop or a longer more flexible arm, as I think the LN one might be a bit too stiff. It works well with the pegs and pushing it down instead of hitting it to get it to set though.
@Jared: The bench is from taking the class with Mike Siemsen (the Naked Woodworker), so it was the lumber that he bought. Pretty sure it's just dimensional / construction lumber from Menard's. @Adam: I think it was thin stock that did it, though I'm not positive. I'll try adding an extra block to see if that helps with the remaining holes. I've also wondered if I have been to aggressive at pounding the holdfasts in (but it is very tempting / satisfying to give them a good wallup).
I think that you do need to have a physically hard wood bench-top to anchor a holdfast, in addition to thickness. I would say that holdfasts grip better in thicker timber – at least 2 inches. Soft pine and the like will tend to compress under the strain of repeated gripping. Sometimes they do slip in the hole and whacking it further often glazes the area of contact, making it worse. An old-timers trick to overcome slipping holdfasts is to ’stitch’ the sides. To do this, work out where the metal is in contact with wood in the hole; this will be below the hook on one side and the opposite part on the back, then stich an irregular pattern with light taps with a centre-punch in both places. The roughened surface will grip the side walls of the hole. Good luck
Shannon I would think that another thickness under the top would be a good fix as well as possibly cutting out a rectangular mortise and adding a new block in that area of a harder material. Also possibly the material added under of a harder species as well. Just my 2 cents.
It is a Nicholson bench made from construction lumber. In the long run it would probably be easier and less expensive to just replace the top.
I had the same problem in my laminated up construction lumber top and mine is 3.5 inches. Happens with both my Gramercy and LN holdfasts. They held great at the start, but then the Gramercies stopped holding in some holes and then the LN after that. I picked up two of the forged holdfasts this past Christmas from Horton Brasses and one from Ed at Roy Underhills school from a local blacksmith and they are still holding great in the same holes. I suspect the issue is the smoother shafts of the Gramercy and LN holdfasts vs, the more rough shafts of the forgred ones. I have tried the sanding of groves around the shafts to limited success, but have not tried dumpling with a punch yet. I will need to try that. In the mean time I recommend the forged holdfasts from Horton Brasses if they still have them. They hold great and were a bargain at the price I got mine.
Maybe there's a brand spankin new tool company with an imminent holdfast product release that addresses this issue...
Would it be possible to dril out the defective hole to a larger size then glue in a hardwood plug?
Thanks, everyone. That's great feedback. I am planning to try different holdfasts; the new ones are on the top of my want-list. Now for the being-patient part. In the mean time, I'll try roughing-up the holdfasts I have. I'll probably try plugging, and re-drilling, too. I'll eventually go with Paul's suggestion, and just replace the top. One thing I am enjoying about the construction-lumber Nicholson is that I don't loose much sleep over experimenting.
I would be tempted to put a 3/4" dowel in the offending hole, fill the enlarged part of it with epoxy, and then drill a new hole an inch or two away. You are loading the wood in compression with the holdfast, so a repair like that should be mechanically fine.
I would guess that the holes aren't oval due to wear, but due to your bench top shrinking. Regardless, have you looked into dimpling your holdfasts to add more grip? I've done this, and it works very very well. See Richard Maguire's video here... http://www.theenglishwoodworker.com/holdfasts-get-a-grip/
Scott check out the English Woodworker on You Tube He solves the problem by using a punch on the inside and outside of the hold fast. I also have Gramercy and it worked for me
If you rebuild the top, could you include strips of hard wood in the line where your dog/holdfast holes are?
holddoa is 95% there. Take off the top and cut out a strip that contains the holes and add a hardwood replacement strip. Drill new holes and you're done. You get to keep most of your old top with it's year of hard earned character.
Could you just glue a piece of hardwood (grain in line with the top) to the underside and drill through that? If the top’s only 2x, I'd think it'd work ok.
I bet adding some texture to the hold self would make a difference. I've been using a 3/4" thick mdf bench top for around 8-9 months now, and all of the dog holes are beat up and oval shaped, but the hold fasts I'm using still hold. They have a pebbled pattern on them - cheap blue painted ones I got from rockler or somewhere like that.
Did you block your top under the holes or are they only in 1 1/2 inch stock? It could be that your top is just a bit soft. I would just drill another hole. My benches are much older than a year and I haven't experienced any failure. I am not big on roughing up the holdfasts unless it is a last resort as I would think it would cause even more wear on the holes.