cutting river rocks for holds . . .

[Matt_Anderson]

So I will have a brand spankin' new climbing gym soon in my brand spankin' new garage.

 

I will be supplementing my hold supply and wish to do so using river rocks (sloper city with perfect texture!). To prevent spinning and also so they won't all be jugs, I intend to cut a fair number of them in half in addition to drilling the obligatory bolt hole (I don't want to glue them to the wall).

 

Anybody done that?

 

Questions:

 

Is there a slick way to hold the round river rocks when taking a wet saw to them? I don't want to wind up like Tommy Caldwell.

 

Same basic question for holding the rock while it is being drilled.

 

I can either rent a wet saw or buy one. If I buy one, I'm unlikley to be able to afford a super high quality one. Will there be a huge difference in the saw for this job. (FYI - if this works out, I am likely to do a lot of stones this way, the gym will be large, effectively filling up a two car garage with 12 foot ceilings, so how long the saw lasts may be a consideration).

 

Can I expect this to be cheaper in the long run than buying holds? Most of the holds will be granite, which I imagine will eat up both drill bits and saw blades.

 

Anybody think I should be limiting the number of river rock's used because they will be to heavy?

 

Matt

[lancegranite]

My dad and I drilled about 50 stone holds.

I just selected rocks that had a flat side.

 

Don't rock saws have built in vices to hold the piece?

[boatskiclimbsail]

I would imagine buying holds will be cheaper in the long run after buying/renting a saw and a handful of blades. You shouldn't have any problem cutting granite with a regular wet saw for tiles/countertops. Just be patient with it.

 

As for holding, consider drilling the hole first and making up a clamping jig that uses the holes for alignment and clamps along that axis. That way you can clamp any size or shape with a single setup. If you really want to get fancy, you could grind the cut side flat using the holes as well.

[dbb]

You might also consider making your holds out of fiberglass resin: http://www.alpinedave.com/misc/holds/hold_making.htm

 

That said, looking for rocks that you can just drill a hole in and bolt up would be great. I would just buy/make the rest.

 

As for weight, rocks are a lot heavier than climbing holds. You should be really careful putting a lot of these on overhanging walls as the only support (I'm guessing) is going to be the structure of your garage which was built to be loaded how it is already. Maybe consult an architect?

[Off_White]

Maybe consult an architect?

 

Getting some consultation isn't a bad idea, but you'll probably do better with a paranoid carpenter who tends to overbuild and understands the forces involved and where to put them.

 

Ages ago I used a lapidary shop at a college to slice rocks in half for a climbing wall. It had a vice and self-fed, a set up more designed for stones than the average tile saw. The blade on a wet saw is no where near as scary as a table saw (which I think was Caldwell's personal trimming device).

[Distel32]

go to vantage and pick up a bunch of those perfect flat holds that are everywhere. They have a flat back so that is taken care off, plus they are pretty versatile.

 

Invite us all over when the gym is done for a pub club boulder sesh.....

[jonthomp]

At risk of giving away a great source of rocks to drill, check out Bedrock on Galer and Elliott (near the grain elevators where the old, old Vertical World was, but on the other side of the street beneath the Magnolia Bridge). They often have presawed river rocks as well as a constant supply of broken pieces of countertop which make for great crimpers on steep walls (the thinner pieces make great screw-on jibs as well). All rocks are sold by the pound and I have put many on my home wall. The river rocks tend to drill easily (I don't know about sawing them) and depending on the countertop pieces, pretty easily as well. Often you can find rocks that just have a flat side as well. When drilling I have just used a 1/2" drill with a mortar bit. I used a 3/4" bit to drill in partway first so the bolt would be recessed and not in the way of your grip. While some holds will shatter while drilling most will hold up just fine and I have never had one snap off my wall even yarding on the 50deg. overhang. I use a Dremel with a grinding bit to frequently sharpen the drill bits as they will dull with every other rock or so. A drill press would help get a better hole with less effort, but the handheld works fine. Enjoy, it's a great cheap source of holds.

[skyclimb]

You will need diamond blades to cut through the rock. Diamond blades run on average around 78-85$ for a 12" blade. They also sell 8" blades for what you will be doing.I am not a expert in geological formation, but river rocks appear to be very hard. I would imagine you will be burning through blades(wet or dry) very quickly. It seems that either buying holds, or hooking on to Jons idea would be key

[ddday]

I have a lot of drilled rocks on my wall. As long as you have 3/4" plywood over 2X4's on 16" centers I wouldn't worry about the structure, it'll carry tons of rocks.

I wouldn't bother with sawing river rocks in half, too much work, whenever I go hiking I keep an eye pealed for rocks with flat backs on them, even some river rocks qualify.

Regarding drilling - I bought a set of masonry bits then starting with 1/8" bit stepped up the holes, with a final counterbore at the end to recess the bolt. Drilling is easier and you get a lot more holes. The bits are cheaper in a set as well. Keeping water on the bit during drilling will help drill life as well.

I have had a few granite countertop holds break, and a slate hold snapped off on me once, so I'd maybe steer clear of using them for ceiling holds, course having said that I have 6-7 on mine.

At one point I thought a rotary hammer drill would be a stellar idea but after shattering 3 rocks I gave up.

In all, it is cost effective, and the natural rocks are my favorite holds, over the 40 or 50 plastic holds I've got.

[Matt_Anderson]

You shouldn't have any problem cutting granite with a regular wet saw for tiles/countertops. Just be patient with it.

 

That's one of the things I was getting at. What difference is there in wet saws besides the quality of the materials/longevity.

 

Faster rotations, I assume make a difference? would they decreaase the inevitable wear on teh blade?

 

I don't know shit about wet saws.

 

And about making the clamping jig - any resources for how to do that?

Edited June 10, 2004 by Matt_Anderson

[Matt_Anderson]

Regarding drilling - I bought a set of masonry bits then starting with 1/8" bit stepped up the holes, with a final counterbore at the end to recess the bolt. Drilling is easier and you get a lot more holes. The bits are cheaper in a set as well. Keeping water on the bit during drilling will help drill life as well.

 

At one point I thought a rotary hammer drill would be a stellar idea but after shattering 3 rocks I gave up.

 

So you just use a standard (beefy) electrical drill for this? Were the holds that shattered good granite or something else?

 

sorry I'm a dumbass about all this.

 

And thanks everyone for the replies.

[Lambone]

I didn't read through all the sugestions here, but you might want to try talking to a geologist...they cut alot of rocks in half.

 

"glen" on this site would be a good person to email.

[scott_harpell]

Regarding drilling - I bought a set of masonry bits then starting with 1/8" bit stepped up the holes, with a final counterbore at the end to recess the bolt. Drilling is easier and you get a lot more holes. The bits are cheaper in a set as well. Keeping water on the bit during drilling will help drill life as well.

 

At one point I thought a rotary hammer drill would be a stellar idea but after shattering 3 rocks I gave up.

 

So you just use a standard (beefy) electrical drill for this? Were the holds that shattered good granite or something else?

 

sorry I'm a dumbass about all this.

 

And thanks everyone for the replies.

 

Yes you can use a regular drill but use masonry bits. You can find them at any hardware store.

[E-rock]

Matt, do you know anyone in the Geology Department at the University of washington?

 

They have a diamond-blade table saw. You can cut rocks of irregular shape very quickly and safely (you can touch the blade as it turns). You can hold the rocks with your hand and push them through the blade.

 

I know this is a long shot, but it's the way I would do it. However, I was in the geology department so I had access to the saw.

[Dru]

you know one thing about using rocks for home wall holds is that they get COLD. in the winter when the most serious training time is, if your home wall is in a garage or basement, they might be so cold as to be painful to pull on. even the rock holds in a gym i used to work at suffered from this problem.

 

wooden holds dont feel nearly as cold during cold temps. also if you buff them up supersmooth they become incredibly hard to use as footholds and hard to use as handholds which is good for training technique on.

 

its easier to customize wood than stone anyways cause you ca use regular carpentry equipment instead of masonry equipment.

[boatskiclimbsail]

That's one of the things I was getting at. What difference is there in wet saws besides the quality of the materials/longevity.

 

A wet saw is basically a chop saw/table saw with a specialized blade and a flush cooling/lubricating system. If you've ever used machine tools with flood coolant you'll know what I am referring to. For cutting stone, water is used where cutting cluid would be used in metalworking. One of those things that just works. The blades are "diamond" tipped, which can mean anything from industrial (fabricated) diamonds to some of the harder carbides found in production houses. The blade typically spins at the same speed, but you may get better results if you are able to play with this a little.

 

And about making the clamping jig - any resources for how to do that?

 

If you're referring to the pin jig I suggested earlier, I can't point you to a ready made one, but the idea in my head consisted of two steel pins with backing plates and some kind of rubber pads. One side would be rigid to some kind of frame and the other side would slide along that frame to different lengths and lock down with a vise-grip/strap clamp kind of device. Probably overkill anyway, just my mind on creative overdrive.