UKC

Hi All,

Some of the older juggy holds I got from my local wall for my home board look as if they would be much less likely to spin if they had set screws. I'd like to drill and countersink some  set screw holes in them and am looking for tips.

What kind of bit do you use?

Do you use a hammer drill? (I'm worried this could crack the holds)

Do you drill smaller pilot holes first?

Anything other tips?

Thanks in advance

Depending on the inner construction I don't know how effective drilling a new hole would be, however on holds without this I've seen setters just drill a screw in against the outside of the hold to stop it spinning.

I use a 3mm masonry bit to make a pilot hole, I don't use a hammer setting and I try to be quite gentle just letting the bit do its thing without pushing too hard. Then drill the hole to required size (I normally do 6mm with a countersink). I haven't cracked a hold yet and I've drilled about 40 holds. There's probably a better method but this works. 

Save yourself the trouble of drilling them (and risk of breaking them) and pin the outside. Put a screw in at an angle either side around the circumference (so the head of the screw just sits over the hold) and it won't spin. 

This is what commercial walls do and what hold manufacturers recommend. 

Thanks for the speedy advice. Yeah, I have put screws around the edge of some of them. There's signs that this has been done quite a bit in the past on some where I can see the holds has chipped away at the edges. I thought about drilling them to increase the lifespan of the holds. I have very limited access to the back so just trying to be really careful to avoid spinners wrecking my t-nut placements.

It depends exactly what they're made from. If they're pure plastic then an HSS twist drill (general purpose metal/plastic/wood, cheap on the counter in a rack in builders merchants) will do. If there's an abrasive filler to bulk out the resin (eg sand) they'll chip and blunt in no time.

Most masonry bits are blunt, designed so the hammer action pulverises and the spiral clears dust, without hammer they aren't inclined to cut anything, I'm surprised to hear of success using them as twist drills but then I've never seen a 3mm masonry drill either so who knows. Could be a terminology issue?

I'd start with a trial hole in the back surface, away from an edge in case it grabs and chips, using a cheap twist drill, see what happens. It should be pretty easy I suspect most modern commercial holds are pure resin.

jk

*Don't* use the drill on hammer. 

As JK says an HSS bit is the best, not masonry, use a high speed. I probably wouldn't bother with a pilot hole so long as you have the hold secured on a workbench or in a vice. 

I've found drilling with HSS bit large for the counter sink first and then the smaller drill size for the screw after is best... I found given the curved shape it was better to centre the hole on the countersink rather than the other way round.... did this on all my moon holds that didn't have a screw hole to pin them

How have you attached your t-nuts and what type have you used? If they're secured by screws or nails, then these are pretty resilient to popping compared to simpler hammer in ones. T-nuts with a 'collar' also mean you're less likely to cross thread when you put the hold on.  

In my experience, it's not that common for a spinner to cause a popped t-nut and its usually caused by cross threading when you put the hold on in the first place. 

In terms of drilling the holds for a set screw, it's a right faff and I'd echo what other have said regarding pinning on the edge of the hold. If you're really concerned about spinners, you could double pin each hold. One screw on the anti-clockwise side (which is the direction they usually spin), and one on the clockwise side too. Hand tightening the bolts with an Allen key often gets them super tight too. 

I used 4 prong t-nuts (the thought of an extra 900+ screws got the better of me). I hadn't considered how they spin one direction more. Sounds like I might be over thinking it then but I've only got a few like that so might try it anyway, summat to do eh! Thanks for all your advice everyone!

You could try a multi-material bit like the Bosch Multi-construction they have a profile similar to a masonry bit but a much sharper point and seem to deal with most things fairly well. I would be tempted to just pin the hold in place with a screw on the outer edge as others have suggested. 

I've drilled a few bolt on holds to make them more versatile screw ons.

If you can get a small scrap piece of ply, drill and hammer an M10 T-nut into it. This gives you a fixture to bolt the hold to and either clamp to a bench / table or a hand vice and gives you something you can drill into.

I've then used a HSS Centre drill or spot drill to start the hole off, these are shorter and stiffer and less likely to squank off on a non-flat surface (usually what a climbing hold is)

A pillar drill makes the job even easier if you have access to one, otherwise a hand held drill. HSS 6MM fast, Countersinks work better at a slower speed.