Author Topic: Multi Montis  (Read 2232 times)

Offline Madness

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Multi Montis
« on: March 03, 2017, 01:35:23 pm »
What size of Multi Montis are people generally using for exploration purposes?

I was thinking of using the 7.5mm x 80mm.

Obviously if what I'm exploring goes anywhere, then larger permanent anchors could be installed.


Offline Simon Wilson

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Re: Multi Montis
« Reply #1 on: March 03, 2017, 02:38:40 pm »
7.5 x 80 or 70 are perfect. Only use reputable good quality brands such as Multi Monti, Fischer, Rawlbolt or Hilti.

 Do not use the cheap ones such as Thunderbolt, Ankerbolt, Lightningbolt, Excalibur, DeWalt.

I have done some research into these 'concrete screws' and I have confidence in the first four brands. Some of the cheapo ones have no ETA, some have ETAs which do not specify an identifiable country of manufacture and some are made in developing countries where adherence to standards is not as well guaranteed.

(ETA = European Technical Assessment)

Multi-Monti ETA :     https://www.asf-fischer.nl/files/artikel_documentatie/dop/ETA-05-0010_en.pdf

Even the most expensive ones cost pennies each so don't even think about reusing them for SRT; there is no point even if you think it looks OK.

You can reuse them in non-critical uses such as hauling boulders, fixing shoring etc.

Use galvanised ones and consider stainless ones of they are  going to be there a long time.

I am keen to see people use 'self-tapping concrete anchors' because they are removable. Please do not install any anchor in a cave which is not removable.

Offline Rob

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Re: Multi Montis
« Reply #2 on: March 03, 2017, 03:14:13 pm »
I thought the 7.5mm ones don't fit through the standard 8mm hanger plates?

I'm sure i've used ones before that go into a 6mm drill hole, but that are a perfect fit for a hanger plate hole....
The end is where we start....

Offline Simon Wilson

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Re: Multi Montis
« Reply #3 on: March 03, 2017, 04:14:00 pm »
I thought the 7.5mm ones don't fit through the standard 8mm hanger plates?
They don't. You need to use a hanger with a bigger hole.

Quote

I'm sure i've used ones before that go into a 6mm drill hole, but that are a perfect fit for a hanger plate hole....

If you want to use smaller screws that's up to you but I'd rather use a slightly bigger hanger.

Offline Madness

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Re: Multi Montis
« Reply #4 on: March 03, 2017, 04:27:42 pm »
Thanks for the replies. That means I can get away without having to buy a rechargeable SDS drill. I don't think I'll be needing to install many.

Offline Mattrees

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Re: Multi Montis
« Reply #5 on: March 03, 2017, 07:30:30 pm »
I thought the 7.5mm ones don't fit through the standard 8mm hanger plates?

I'm sure i've used ones before that go into a 6mm drill hole, but that are a perfect fit for a hanger plate hole....

That's what I've used when bolting up avens. 6mm x 50mm Thunderbolts have held a FF1 fall.

Long term rigging maybe a different matter, but for exploration, that's what I use. 6mm x 50mm holes are great for maximising battery life.


Offline andrewmc

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Re: Multi Montis
« Reply #6 on: March 06, 2017, 06:20:09 pm »
These should be pretty removable if you are only aiding upwards... (with an occasional proper bolt!) :P

http://www.bolt-products.com/StainlessSteelPitons.htm

Offline Madness

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Re: Multi Montis
« Reply #7 on: March 06, 2017, 10:08:44 pm »
These should be pretty removable if you are only aiding upwards... (with an occasional proper bolt!) :P

http://www.bolt-products.com/StainlessSteelPitons.htm

Thanks for the link. They're dirt cheap. Anyone on here ever used them?

Offline Mattrees

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Re: Multi Montis
« Reply #8 on: March 17, 2017, 01:52:26 pm »
These should be pretty removable if you are only aiding upwards... (with an occasional proper bolt!) :P

http://www.bolt-products.com/StainlessSteelPitons.htm

Thanks for the link. They're dirt cheap. Anyone on here ever used them?

They scare me.

Does anyone have a source for 7.5mm (6mm hole) stainless anchors?

Offline Huge

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Re: Multi Montis
« Reply #9 on: October 04, 2017, 11:29:03 am »
I thought the 7.5mm ones don't fit through the standard 8mm hanger plates?

I'm sure i've used ones before that go into a 6mm drill hole, but that are a perfect fit for a hanger plate hole....

That's what I've used when bolting up avens. 6mm x 50mm Thunderbolts have held a FF1 fall.

Long term rigging maybe a different matter, but for exploration, that's what I use. 6mm x 50mm holes are great for maximising battery life.

I've been using through bolts for climbing but it may be a good idea to use screw-ins as they can be screwed out again, not so much to re-use them but so bolts aren't left behind all the way up a wall. I always over drill the holes for through bolts so they can be tapped in afterwards and covered by a little mud.

I'm a bit confused as to what hole diameter is required for a particular size of screw-in bolt. Am I right in thinking that 6mm bolts actually need a 5mm hole, rather than 6mm as alluded to in the quotes above and the 7.5mm bolts need a 6mm hole? Don't understand why 7.5mm bolts don't fit in 8mm hangers.

Any help in clearing this up would be much appreciated, thanks.

Offline pwhole

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Re: Multi Montis
« Reply #10 on: October 04, 2017, 12:35:34 pm »
I'm not familiar with that particular brand, but they generally all need a bigger hole in the hanger plate than the rock, as the thread projects to a greater diameter than the shank. An 8mm bolt actually has a thread diameter of about 9mm, so you have to use a 10mm plate. Incidentally, premium Hilti screws are not exactly cheap, at £1.78 per pop:

https://www.hilti.co.uk/anchor-systems/screw-anchors/r3241612

Offline Huge

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Re: Multi Montis
« Reply #11 on: October 04, 2017, 01:41:20 pm »
Cheers for that.

It's the Multi Monti bolts I've been looking at. Their website says that their 6mm bolts need a 5mm drill bit and 7.5mm need a 6mm bit. This where I'm getting confused.

Offline Mattrees

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Re: Multi Montis
« Reply #12 on: October 04, 2017, 02:03:44 pm »

I'm a bit confused as to what hole diameter is required for a particular size of screw-in bolt. Am I right in thinking that 6mm bolts actually need a 5mm hole, rather than 6mm as alluded to in the quotes above and the 7.5mm bolts need a 6mm hole? Don't understand why 7.5mm bolts don't fit in 8mm hangers.

Any help in clearing this up would be much appreciated, thanks.

Different manufacturers list them in different ways, some will list by drill bit diameter, others by thread clearance (hanger) diameter. I'm using Thunderbolts, these are usually listed (but not always) by bit diameter. I'm drilling 6mm holes and using 8mm hangers.

The Hilti ones are very expensive, I'm still looking for a reasonably priced source of stainless anchors.

Offline Mattrees

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Re: Multi Montis
« Reply #13 on: October 04, 2017, 02:20:08 pm »
Cheers for that.

It's the Multi Monti bolts I've been looking at. Their website says that their 6mm bolts need a 5mm drill bit and 7.5mm need a 6mm bit. This where I'm getting confused.

Have you found anywhere in the UK to buy them?

Offline Huge

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Re: Multi Montis
« Reply #14 on: October 04, 2017, 03:13:43 pm »
Cheers Mattrees.

I found the Multi Monti bolts listed at InterTools, who are based at Ilkeston in Derbyshire. They only list 6mm and 7.5mm, which must be the outside diameter of the threads, with the shafts of the bolts being 5mm and 6mm respectively. I suppose the size of bolt you are using would be their 7.5mm.

http://www.intertoolsonline.co.uk/heco-schrauben/fixings/masonry-and-concrete/multi-monti/multi-monti-hex-head-range

Offline Canary

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Re: Multi Montis
« Reply #15 on: October 04, 2017, 06:13:51 pm »
Has anyone used these in situations where you could take dynamic falls???

Offline Mattrees

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Re: Multi Montis
« Reply #16 on: October 05, 2017, 08:40:48 am »
Has anyone used these in situations where you could take dynamic falls???

Yes and tested them!

Offline SamT

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Re: Multi Montis
« Reply #17 on: October 05, 2017, 09:13:13 am »

Yes, I sometimes equip climbing routes with these initially, with a view to replacing them with proper resins once the route is worked and established.

The advantage is that if the initial placement is not quite in the right place for easy clipping, its straight forward to just unscrew and move.  Once the right place is found, the same hole can be re-drilled larger, and a resin bolt installed.

I've always found that I can get the 8mm (drill size) ones, through a normal petzl hanger with a 10mm hole no problem.  I had some larger 10mm ones that would go through a 12mm hanger, but had to be screwed on over the threads.

Has anyone thought of/tried using an impact driver to place these?

Offline pwhole

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Re: Multi Montis
« Reply #18 on: October 05, 2017, 10:05:33 am »
I've used an impact driver at work on them, driving into concrete, though the first batch of screws we were given were so cheap and nasty I ended up taking in some of my Excaliburs the next day, which worked fine. Cleaning the holes our properly is critical unless they're massively over-drilled, as it's the dust that jams/blocks them. My main concern with the impact driver is not being able to 'feel' the rock like a hand-driven one, so any holes or weaknesses may not be as apparent. That said, I did some bolt-climbing with them recently, and screwing them in at full stretch perfectly perpendicular to the hole was not easy at all, and one or two ended up getting jammed, so had to pull out and re-screw. So I can see for climbing, an impact driver (especially one with torque control) might actually help quite a lot, though a lot more expensive than a ratchet spanner.

Offline JB

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Re: Multi Montis
« Reply #19 on: October 05, 2017, 01:59:47 pm »
Has anyone used these in situations where you could take dynamic falls???

Worth being aware of this - https://www.thebmc.co.uk/bolt-failures-on-north-wales-limestone

Offline Dave Tyson

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Re: Multi Montis
« Reply #20 on: October 05, 2017, 02:11:55 pm »
I think Miles Moulding had some issues with thunderbolts (or equivalent) in Cwmorthin. A couple of bolts failed under very light loads after they had been in situ for some time - the head came off one and IIRC the other snapped a little way into the rock. It may be if the bolt is overtightened there is some residual stress which might cause microcracks over time. The problem is that even if you tighten the bolt so the plate hanger is just nipped someone may come along later and decide its a bit loose and tighten it further...

I'll be happy to use them for exploratory climbs, but wouldn't consider them for permanent placements due to the above issues.

Dave

Offline Mattrees

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Re: Multi Montis
« Reply #21 on: October 05, 2017, 02:39:18 pm »
It may be if the bolt is overtightened there is some residual stress which might cause microcracks over time. The problem is that even if you tighten the bolt so the plate hanger is just nipped someone may come along later and decide its a bit loose and tighten it further...

I'll be happy to use them for exploratory climbs, but wouldn't consider them for permanent placements due to the above issues.

Dave

I place throughbolts for belays buys that's more because of corrosion concerns - still no viable source for stainless multi montis.

I've had heads shear through being overtorqued, both by hand and with an impact driver, cleaning out the hole is important.


Offline Simon Wilson

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Re: Multi Montis
« Reply #22 on: October 06, 2017, 04:56:37 pm »
I've been testing these but I haven't made the time to write it up yet although it shouldn't be long. I want to encourage people to use them. They are far superior to throughbolts from a conservation point of view. Throughbolts are a curse and a menace to our caves and crags

Just a few comments.

Only use quality concrete screws and Multi Monti are one of the good ones. Avoid Thunderbolts and other cheapo brands. The one that failed in the BMC report was a Thunderbolt.

The 7.5mm Multi Montis (6mm drill) are pretty bomb-proof when used correctly. They have a simliar strength to an 8mm 'high tensile' (8.8 steel) bolt. 10mm Multi Montis (8mm drill) are nearly twice as strong - double bomber.

Follow the instructions supplied with them particularly about cleaning the holes.

They need to be drilled perpendicular and driven in straight. I would not recommend using an impact driver. It is best to be able to feel it as you screw it in and tighten to the correct torque. The correct torque is just tight enough to be secure and no more. Do not overtighten it.

They are easy to buy from a number of UK suppliers - just shop around.

Here you go - Multi Monti 7.5 x 60 at 30p each -   http://www.intertoolsonline.co.uk/heco-schrauben/fixings/masonry-and-concrete/multi-monti/multi-monti-hex-head-range

or

https://www.tradefixdirect.com/unifix-thunderbolt/heco-fix-multi-monti-flanged-head-75-x-60mm

Online maxf

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Re: Multi Montis
« Reply #23 on: November 28, 2017, 12:28:09 pm »
So what hanger size is recommended for the 6mm drill (7.5mm screw) type ? Might an 8mm hanger be a bit 'loose' ?

Offline Mattrees

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Re: Multi Montis
« Reply #24 on: November 28, 2017, 01:46:07 pm »
So what hanger size is recommended for the 6mm drill (7.5mm screw) type ? Might an 8mm hanger be a bit 'loose' ?

8mm hanger works fine, the bolts will fall out if you're not careful. I tried using o-rings but decided it wasn't worth the trouble.