glue and a blade mount

[mountainpenguin]

Hi all
I have a petzl meteor helmet its very comfortable and fits my odd shaped head well.
I would like to add a blade mount to it to use a sten. The helmet is made of expanded polystyrene and so drilling is not an option.
I was wondering if anyone had ever successfully glued a blade mount to a helmet using araldite or somthing similar.
How successful was it ?
Thanks in advance David

 

[Charlie]

Most glues contain solvents that will dissolve polystyrene, any glue you plan to use needs testing on a separate piece of material first.
It may also be possible to create some sort of mounting using a velcro band through the two holes in the front of the helmet - some bodging required but this may be your best option.

 

[traff]

Epoxy resins (e.g. araldite) are fine to use on polystyrene. Any weakness will occur in the relatively small contact area where the mount meets the helmet. I would re-enforce a small area using glass cloth and an epoxy laminating resin then bond the mount to the fibreglass.

 

[mountainpenguin]

Is the outer shell of a meteor polystyrene as well?
I like the idea of fibre glass would you embed a set of screws in it ?

 

[Les W]

The outer shell of a Meteor III is polycarbonate
http://en.petzl.com/petzl/SportProduits?Produit=603

Have you thought about this product as a way forward?
http://www.caving-supplies.co.uk/cgi-bin/psProdDet.cgi/13340

 

[Mark-Cal]

Spookily enough I have a Petzl Meteor and a Sten mounted to it.

Why do you say drilling isn't an option?
I've fitted my blade mount by drilling through the front and used thin stainless nuts and bolts with decent width washers internally to stop the nuts pulling through and it's lasted a couple of years now without any problems.

 

[mountainpenguin]

oohhh that sounds ideal!
do you have any pics ?

 

[SamT]

:-\

is the meteor suited to caving (I assume thats what you want to mount a sten for).

Am I right in thinking that the polycarbonate shell is only very thin and flexible, therefore, is the polystyrene underneath going to constantly take a battering whilst caving. i.e. a bonk in the head in a low bit is going to actually properly damage the 'absorbant' layer of polystyrene underneath. I cant see the helmet lasting that long if so. Would an Elios not be better suited. or Ecrin.

(clearly that involves shelling out more cash which is what I presume you are trying to avoid doing).

 

[Cave_Troll]

I suspect that if someone's made it work for a couple of years, then it has some use as a caving helmet.
Similarly some people would say that a Myo XP is not a caving light, but i've used one for 2 + years...

Personally i'd be worried in a polystyrene caving helmet that the polystyrene would crack and degrade performance, possibly in a non visible way.

 

[mountainpenguin]

I have tried a few helmets over the years.
I have a big lump on my head and most helt mounts rub on it but the meteor doesn't
Ill keep a good eye on. A large impact causes them to split (had this happen to a bike helmet once and was unconscious for a long time)

 

[Mark-Cal]

do you have any pics ?

I do now. 
Forgive the state of it, I've not cleaned it from yesterday yet...

The bolt heads fit nicely each side of the internal central rib of the helmet so they're well clear of your forehead.

I've not found any problems using the Meteor yet and although I've never chucked it down Titan it hasn't exactly had an easy life. There's a few slight dents in the outer shell where I've forgotten to duck at various times but no sign of obvious damage to the internal moulding. I guess the problem, if there is one, is whether such damage would be noticable if it existed.

It was sold to me as suitable for caving (although the CE label inside says only suitable for climbing) and I've been really happy with it over the time I've owned it, it's lovely and light with plenty of ventiation and since fitting the Sten to it I haven't used anything else.

 

[Pete K]

It was sold to me as suitable for caving (although the CE label inside says only suitable for climbing) and I've been really happy with it over the time I've owned it, it's lovely and light with plenty of ventiation and since fitting the Sten to it I haven't used anything else.

The Elios lid has the same 'climbing only' sticker, yet Petzl have bolted a Duo to it for sale as a Spelios.

I must admit I'm not sold on the Meteor as a caving lid and I agree with Sam T. The shell is too flexable and I'd be really worried about having a frontal impact pushing the bolts into my forehead. Maybe it would be better if the nuts and washers sat touching the plastic shell on the inside, i.e. if you bored out the polystyrene to allow them to pass. This would be similar to standard fittings then.
This may be what has been done, but it doesn't appear so from the picture.

 

[Mark-Cal]

The bolt heads are recessed slightly but if I buried them completley the mount would be relying only on the thin outer shell to keep it in place and would snap off at the first knock it received.

 

[mountainpenguin]

Ahh  thats a meteor III, the new one. Mine is the older version that doesnt even have the funny clips for a strap!
As for the bolts a blow would have to be to the bolts themselves. Hitting the lamp would crush the shell before the bolts were rammed into the skull!

 

[Maisie Syntax]

The UK distributor for stenlight ( www.excellentstuff.co.uk ) do a helmet/headstrap to mount a blade fit sten. They look similar to the one from caving supplies mentioned by Les W but they retail for a gnats under ?30 - ouch.

Do they do potholing helmets as opposed to caving ones?
Have seen insurance policies differ between these terms, wondered if it could be missapplied to helmets as well?

 

[Christian_Chourot]

Do they do potholing helmets as opposed to caving ones?

Is there a difference?

 

[graham]

The Elios lid has the same 'climbing only' sticker, yet Petzl have bolted a Duo to it for sale as a Spelios.

That's 'cos you can't cave with it until a light has been bolted on. 

 

[Maisie Syntax]

Do they do potholing helmets as opposed to caving ones?

Is there a difference?

In the real world - no, but I've previously come across an insurance policy that covers you for potholing but not for caving . They couldn't define either term. Sorry that this has gone a bit off thread.

 

[graham]

Still OT, but I was always amused by the insurance policies that specified you could only go caving to a limited depth. Wonder how they cope with people going into resurgence caves.