Z-MAC rivets

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mucci

Trad climber
The pitch of Bagalaar above you
Topic Author's Original Post - Jun 4, 2010 - 05:22pm PT
What is the standard rivet these days?

I was given 35 Z's, brand spanking new.

Gotta say I would prefer them to a 1/4" x 1" Button head.

Great design, pound the nail, expand the sleeve, lots of contact with the rock.

5/8ths drilling depth, 3/4" total length.

Any strength issues, beyond what a rivet is intended for?

Let's hear it from those who have used the Z's

Mucci
Mungeclimber

Trad climber
sorry, just posting out loud.
Jun 4, 2010 - 05:54pm PT
Aren't the Zs the ones that we hear horror stories about? (total speculative questioning on my part)

Strider

Trad climber
one of god's mountain temples.... ಠ_ಠ
Jun 4, 2010 - 06:05pm PT
I noticed they use z-mac rivets to secure the toilet paper holders to the walls of the vault toilets at the Leap and in Josh. Probably the best use for them, I would prefer to clip a new 1/4" buttonhead than a z-mac. No real evidence to support my prejudice though...

-n
nature

climber
Tucson, AZ
Jun 4, 2010 - 06:22pm PT
aluminum dowels all the way.

Charlie Porter and Jean-Paul de St. Croix were onto something back in the day.


I did The Trip before the rebolt and after. Nothing like back cleaning dowels for 30 feet just in case one goes and you zipper the whole pitch. It'd suck to drill new holes after shearing all that Al.

cheap too.... leave the swaged cable for something else though....

seriously though.... if you want something of small diameter and not very deep I picked up these stainless 1" X 1/4" studs. They don't look very strong but they are SS. They freak you out like any good rivet should.
Strider

Trad climber
one of god's mountain temples.... ಠ_ಠ
Jun 4, 2010 - 07:12pm PT
I thought SS was softer and slightly weaker than normal plated Steel...?

-n
Erik Sloan

climber
Jun 4, 2010 - 07:51pm PT
Thanks for posting this Mucci.

Z-Macs make very poor rivets. If you don't own the land where you planning on placing them, please refrain from doing so.

I want to say that the Z-Mac utilizes a steel nail pounded into an aluminum sleeve, but I"m not positive about that....
What I am positive about is Z-Macs are more susceptible to working their way out of the hole over time, possibly because of freeze and thaw cycles, than any other rivet I've seen used in Yosemite. I fell fifteen feet onto a well-placed Z-Mac on Ten Days After, BITD, and ended up going all the way to the 1/4"ers at the belay cause the thing sheered right off (I thought the rivet hanger had just jumped off the rivet till I got back up there. Long day, needless to say).

I don't think the buttonheads are that great either, as they are difficult to get tight in the holes. They are the best solution we have for now.

If I was a Dreamer:
The best bet seems to be a 3/8" X 3/4" sleeve that would take a 1/4" or slightly bigger machine head, so the whole setup could be stainless. Course we'd need to get our drilling rigs dialed so we could drill 3/8" X 1" in a couple minutes.

cheers
e
Slabby D

Trad climber
B'ham WA
Jun 4, 2010 - 08:10pm PT
So, thread drift, but in regards to upgrading rivet ladders....

If you pull an old rusty 1/4" buttonhead out of a hole (and there is no visible damage to the hole) can you simply replace it with a new 1/4" buttonhead of the same length? Or will the holding power be compromised?
Erik Sloan

climber
Jun 4, 2010 - 08:35pm PT
Another excellent question.

Done it. Don't recommend it.

Holding power significantly compromised.

Funny story, back in the mid-90s, before much bolt replacement had happened in Yosemite, I suggested this, pull and replace, method to Steve Gerberding. I was like, 'hey, replacing on those 1/4"ers is gonna be easy, just pull out the old one, drill it a little deeper, and put in a new longer one.' Steve was like, 'I don't think it works like that. I'd check with the bolt manufacturer before you try it'. hahhahaha

(I did it on the first pitch of Eagles Way. Pulled the old bolt, drilled out the hole and put in a new one. Went in way too easy even in a perfect looking hole. Went back in '04 and replaced 1/4"er with 3/8"er.)

Amazing to think that 5 years later Tom Frost and Chris McNamara would be convincing me that 3/8" bolts were all that was worth putting in a drilled hole.

cheers
e
mucci

Trad climber
The pitch of Bagalaar above you
Topic Author's Reply - Jun 4, 2010 - 08:51pm PT
Good stuff here.

They are a soft expansion sleeve type with the nail that is then pounded in flush to expand the unit.

The same issue with sustainability could be argued against the machine head (threads ground down).

Based on the nature of a rivet (short), 1" button heads don't really do it for me. Might as well throw a hanger on it and drill an extra 1/8". I have always treated rivet ladders as body weight only climbing. So the occasional odd bolt in the ladder eliminates the need for 3/4" rivet placements.

Fixe 5/16th blow, that has been the consensus here anyway.


So SS machine heads, due to high sheer strength, better weathering...etc is the next best option for short placements.

I have not been on any newly established wall routes, but I highly doubt the buttonhead is the standard for rivets.

Thanks for the words, maybe some z-mac vets might chime in with some first hand experience.

Mucci



mucci

Trad climber
The pitch of Bagalaar above you
Topic Author's Reply - Jun 4, 2010 - 08:57pm PT
ec

climber
ca
Jun 4, 2010 - 09:33pm PT
'used lot and lots of zmacs.

'dunno about their longevity, but I had one hold a hard 8' fall with a 3/32nd" wire hanger on it, thought that the hanger would blow or shear it off, but didn't budge. I normally had longer ones and left just enough sticking out (like Porter's) to use these 1/2" tubular slip-knot hangers I made on them (these would not fall off, like slinging a knob).

'Guess we were just thinking about getting through at the moment, not the future. No one ever repeats my routes anyway...LOL

 ec
Salamanizer

Trad climber
The land of Fruits & Nuts!
Jun 4, 2010 - 11:55pm PT
Mucci, Z-macs are total crap. I've had the pleasure of pulling quite a few and not one pulled with much restraint. Kinda like pulling a finish nail from wood. Several snapped off at the head pulling the nail with it leaving the soft aluminum sleeve inside the hole. Which consequently is pretty easy to drill out.

Don't use em' chuck em'. 1/4" x 1" split shaft rivets work great in solid rock for aid. 1.5" is bomber for lead bolts but will need to be replaced sooner than later. In softer stone I don't really know, I'd go with a 3/8" bolt unless it's really crap, in which case you make adjustments based on experience and not second hand knowledge.

Whatcha puttin up?
ec

climber
ca
Jun 5, 2010 - 12:10am PT
1/4" buttonheads are fine if you want to drill a deep hole = way more time on a aid ladder...just sayin'
mucci

Trad climber
The pitch of Bagalaar above you
Topic Author's Reply - Jun 5, 2010 - 01:14am PT
I am sure many of us have seen all kinds of hardware used for progression on wall routes.

Sure after a few decades most bolts/rivets are going to show signs of weathering.

I have stories of every kind of bolt/rivet going bad in one way or another.

How many times has the head snapped off a spit shaft? Very frequently in my experience.

A irregular hole would accept a Z-Mac, and with more surface area of metal on rock than a button head/machine head.

Most Z's you see are at least 15-20 years old. Seems like they have the same life span of many 1/4" button heads placed with hangers that I run into.

I would not consider the Z-Mac to be a piece of protection, rather a piece for progression. Same goes for a machine head.

Certain rivet ladders used to define routes, now each placement has to hold a fall?

Next thing I am going to hear is "Why not just place 3/8 button head"

* Of note, a short hole does not hinder the nail from being driven completely flush.

Just trying to get a little info on these buggers, thanks for the replies.

Mucci

Sal- The wheel is always turning.....the less drilling the better.



ec

climber
ca
Jun 5, 2010 - 01:30am PT
...now each placement has to hold a fall?

bullsh#t, isn't it?

It only has to hold body weight...

BYOBolts
Mimi

climber
Jun 5, 2010 - 01:31am PT
"I would not consider the Z-Mac to be a piece of protection, rather a piece for progression. Same goes for a machine head.

Certain rivet ladders used to define routes, now each placement has to hold a fall?

Next thing I am going to hear is "Why not just place 3/8 button head.""

mucci, a machine head is a lot more solid and it shouldn't be insinuated that it's anything like a ZMac POS. And is anyone really saying that about rivet ladders?

FWIW, before starting another mank thread, you might try a quick search.
http://www.supertopo.com/climbers-forum/15193/Rivets
mucci

Trad climber
The pitch of Bagalaar above you
Topic Author's Reply - Jun 5, 2010 - 01:54am PT
Hey Mimi-

I do believe that the Z and 1/4" x 3/4" are comparable. Both have held falls. Both have a very small margin for placement error.

Yes I do think that when speaking of placing a 1" button head in place of a rivet you are now talking about protection placements.

I did check that thread, in which Z macs were mentioned by Minerals once. The thread is 7 years old.

Mimi what examples of Z-Macs lead you to believe they are unsatisfactory for progression placements?

Mucci
Mimi

climber
Jun 5, 2010 - 02:11am PT
Their longevity and strength are poor. And the intent for which they were designed. They're for hanging signs! People using them either didn't know better or they were being cheap.
mucci

Trad climber
The pitch of Bagalaar above you
Topic Author's Reply - Jun 5, 2010 - 02:26am PT
Thanks for the reply Mimi.

Mungeclimber

Trad climber
sorry, just posting out loud.
Jun 5, 2010 - 02:27am PT
are we suggesting that if one drills a hole, then it should be filled with a standard protection bolt, and that there is no place for 'aid bolts' for progression upward?
mucci

Trad climber
The pitch of Bagalaar above you
Topic Author's Reply - Jun 5, 2010 - 03:01am PT
I don't think anyone made a direct comment as to the strength a placement needs to be on a rivet ladder on this thread.

But when I hear "Use 1/4" x 1" split shaft button heads as rivets, I think protection placements.


Edit : 5/16ths x 3/4 might be the ticket.



Erik Sloan

climber
Jun 5, 2010 - 03:47am PT
Good discussion gang.

I don't agree with you Mucci about the machine heads. Having pulled hundreds of them I can assure you that most are not placed optimally, such is the variance of rock and the inconsistency with which anyone places them. Back in the 80s and early 90s the folks placing machine heads were doing a lot of FA's, and were more in tune with the inconsistencies in the rock and the necessity to vary the hole diameter, by drilling sloppy or tight holes depending on rock hardness in that position, than any climbers are today. Even those of us that learned in the 90s did a poor job of learning the trade--Chris Mac tells a great story of his route on the Northwest Buttress of Half Dome(Una Iglesia), where machine heads splintered the rock around the hole on one pitch and later one came out while he was standing on it due to the different nature of the rock.

No doubt, the scars that are created from removing an aging machine head eliminate the possibility of reusing the old bolt hole. That alone should be reason to consider the buttonhead as a better option for now for creating sustainable, upward-progress-oriented placements.

North American climbing history is replete with FAist using whatever bolting techniques were common at the time and later greatly regretting these actions. The choice is always there-follow the status quo or consider what might last longer and be more readily replaced in the same location. Dave Turner even told me he regretted using machine heads on Block Party and switched to more buttonheads on Atlantis.

Let's us this attention to visual the best possible rivet for bigwall climbs. We can create whatever we need.

cheers
e
ec

climber
ca
Jun 5, 2010 - 05:06am PT
I didn't mention that we'd bathook 'bout a half-dozen moves, then a zmac, a half-dozen bathooks, then a 1/4" buttonhead...

that'll get some of yer panties in a bunch...

cheap? maybe...efficient? Hell Yes!

 ec
Greg Barnes

climber
Jun 5, 2010 - 05:49am PT
Any strength issues, beyond what a rivet is intended for?

Strength ratings - ultimate load:

1/4" Zmac: 890 lbs tension, 880 lbs shear

1/4" buttonheads: 1,760 tension, 2,090 shear

from www.powers.com/mechanical.html

And while we're at it, take a look at the stats for 3/8" Lok-bolts, which you will see here and there - they snap easily (as Marty Lewis and Peter Croft found at Owens when doing a few routes with them):

3/8" Lok-bolts: 2700 tension, 2,440 shear

For comparison, short 3/8" 5-piece (Power-bolt): 5915 tension, 7440 shear

And for those stainless stud bolt lovers: short 3/8" : 3040 tension, 3760 shear. These stats used to be better (still not as good as the 5-piece), so it would be interesting to see why they are so low now...half the strength of a 5-piece.


The short of it is keep those Z-macs for sticking a sign on a concrete wall or TP in the bathroom...
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