|By Aaron Cromer |
From Tucson, AZ
Oct 7, 2009
What kind of bolts should i use to place in sandstone??? I will be placing bolts just for a rappel. So glue in's are not really an option since i am going to use it right away. thanks
|By mtnkid85 |
From Billings MT
Oct 7, 2009
Glue ins. Depending on quality of rock anything from 3/8x3" to 1/2x4.5"+.
Do some searching on here and over at rc.com, theres been a fair bit of disscusion on Sandstone bolting.
|By Skyler Penrod |
Oct 7, 2009
Around Moab I have seen and heard people using 3 1/2x1/2 inchers.
|By Mike Anderson |
From Dayton, OH
Oct 7, 2009
It's pretty much the same story as any other rock type. The best thing you can place is a stainless glue in, the worst is probably a carbon steel stud bolt. Use the best you can afford.
Glue in's are pretty useless unless you are bolting on rappel because you can't use them immediately. If you're using a bolt gun, then you should use 1/2 inchers at least. They'll cost a bit more, but won't take any more time or battery juice to drill. If you're hand drilling on lead, you'll probably want 3/8" bolts, but if you're just placing belay bolts, it actually doesn't take much longer to drill a 1/2 inch hole, even by hand, and you'll be way more psyched on the results.
Powers five-piece bolts seem to work pretty well in sandstone, but they should be at least 3" long...the wider the better. To reduce spinners, tap the bolt in the hole partway, then snug up the bolt finger tight, then tap some more, re-snug, etc. If you just pound the bolt in there all at once with out snugging it, you may never get the sleeve to tighten on the cone because the holes get too big in sandstone. You could also try using an undersized bit... ala a metric, but I've never tried it. Also, resist the urge to overtorque the bolt. In fact, you should probably undertighten it. You probably won't be able to tighten the bolt as high as the specs dictate (25-30 footpounds, I think).
|By Brian in SLC |
From Salt Lake City, UT
Oct 7, 2009
Mike Anderson wrote:
Powers five-piece bolts seem to work pretty well in sandstone, but they should be at least 3" long...the wider the better. To reduce spinners, tap the bolt in the hole partway, then snug up the bolt finger tight, then tap some more, re-snug, etc. If you just pound the bolt in there all at once with out snugging it, you may never get the sleeve to tighten on the cone because the holes get too big in sandstone. You could also try using an undersized bit... ala a metric, but I've never tried it.
12mm is slightly smaller than 1/2", 10mm is slightly bigger than 3/8", for reference.
For powerbolts, I think if you're in fairly hard sandstone, especially with a patina on it, where the outside is harder than the inside, I've had better luck with shorter bolts. Since the cone needs to both bite and not bind, driving longer distance into soft rock sort of is a diminishing return. Also, I think its super important to really brush the hole out well, and blow out the dust with a bulb, as well as drill the hole deeper so the crud pushed by the cone has a place to go in the hole.
I think the tap, snug, tap method works pretty well. And, tap the bolt, don't beat the heck out of it. Take a good look at how the bolt actually tightens and think along those lines.
Long 3/8" stainless are really hard to get to snug in sandstone, especially the softer stuff in So. Utah. The cones seem so much softer and prone to damage than non-stainless, so, you have to be pretty crafty and careful setting them. Also, be prepared to yank them if they don't seat.
Hanger location surface prep is important, too. Try to get that hanger flat, with no crystals or loose debris under it. Since you won't probably be torquing them down super tight, they'll get looser faster if the hanger isn't perfectly situated. I almost wonder if you can't get a flat placement, to use some of that concrete putty (or JB weld) to balance out the low/high spots so the hanger sits flush. I've done that and it seems to work pretty well in keeping constant tension on the hanger.
My bet Sam L. knows some tricks too. Seems like he's been doing a bunch of anchor work in the Moab area.
-Brian in SLC
|By Sam Lightner, Jr. |
Oct 26, 2011
I just had this link sent to me... not sure when it last came up.
Without question a glue in is the best bolt for our soft rock,a nd by that I mean all of the rock on the Colorado Plateau. However,Mike is right and they are not too convenient unless you are rap bolting. Also, make sure you don't brush the hole TOO much... the rock is so soft you are actually brushing sand off the holes edge while brushing. A few bushing, then blowing cycles, with the end being blowing, is best...
The five piece is the best of the expansion stuff. Sadly, our rock is often too soft, even when varnished, to take on the 4 inch bolts. The rock will actually collapse inside the hole as the bolt is banged in. This then leaves you with a $12 spinner that cannot be removed but is not going to last. Most of what I place are 2 3/4 5 piece SS bolts and they almost always tighten up. In real soft rock I use STRIKE anchors that are 5 inches long. They are not ss as I can't find any strike anchors that are, but the half inch diameter combined with the length mean they will probably outlast the rock you are putting them into.
As a side not for everyone.... I'm almost 45 and have been putting up routes since Reagan was president. I used to think that carbon bolts were fine cus they seemed to me to last so long. I realized about 10 years ago that I was going around replacing my old stuff and if I'd put iin SS I would not be. If everyone used SS we would not have to replace almost ever. So, my advice to everyone is to spend the extra money and buy SS.
|By Ben Beard |
From Superior, AZ
Oct 29, 2011
depending on the situation, you could always use glue ins and rap on gear. Depends if there are gear placements and if you want to leave it up there till the glue sets.