UKC

Specifically fibreglass ones? Me and a friend are building a tall thin one so that we can hand jam our way up the local wall.

They gave us some instructions which are as follows:

- Create a frame out of plywood
- Fill with expanding foam
- Remove frame and carve hardened foam to desired shape
- Layers of fibreglass and resin go on
- Once hardened, trim edges, wet and dry sand it
- Paint appropriately.

Won't have any holds bolted onto it so not worried about t-nuts. It will be attached to the wall with screws through a....flange....around the edge.

Does that sound about right?
Roughly how many layers of fibreglass do you reckon will be needed to make it strong enough? I've done plenty of fibreglassing before but thats always been on yachts and dingys so not sure about a structure like this.
Keep the foam inside the volume? Or take it out?

Any hints/tips?

Cheers all!

Benny

In reply to bennycattrall:

I'm not an expert but that all sounds reasonable. I'd leave the foam in to give more rigidity - particularly if any of the faces are large. I guess the number of layers depends mainly on the weight of the matting an the size of the faces.

I'd be interested to know how you get on - I might be tempted to do something similar in future!

In reply to bennycattrall:

just buy a pair of jamming ones, http://www.hangfastclimbing.co.uk/products/bespoke-volumes/

In reply to bennycattrall:

Sounds like a fun project.

Surprised a commercial wall would let you put them up though . I would have thought they would have to come from a supplier in terms of being safe,tested and fit for purpose etc ?

Just think by the amount of detail you are asking about how to do it that it might not be the most structurally sound product, or I might just be a namby pamby. JI was thinking that if I made one I wouldn't want someone to end up with it on their head or slicing there hands if it broke in use.

In reply to bennycattrall:

Sounds reasonable as a structure if a little pricey and messy, personally I'd look to wood and simpler shapes.

I'd have thought with the foam left in a small ish volume and compound curved surfaces you could get away with 4-5mm of glass while maintaining decent rigidity, more and ideally lighter glass at the the mounting flanges. For bigger surfaces or flat surfaces or a hollow volume I'd shoot for at least 6-8mm of glass then beef it up as required once cured to suit the shape. How many layers depends what weight of mat/cloth you're using and whether you use any core filler.

jk

In reply to bennycattrall:

I don't know about volumes, but from electricity industry have some experience with fibreglass ladders (non-conducting, so in substation yards they are preferred for certain uses). When they get worn they can start to shed fibres which you then find in between your fingers and wherever else you manage to transfer them to.

This experience would lead me to believe you want to make sure that the top painted(?) surface is sturdy and will both protect the fibreglass resin matrix from getting worn, and keep your skin away from fibres. Also maybe good to recondition it from time to time before gets too worn.

Someone else may have more direct info for you, but just wanted to share a possible risk (an annoyance more than a danger, in general, but I hate the feeling of fibre-glass bits on skin, and get paranoid I'll transfer them to my eyes or more "delicate" bits).

In reply to bennycattrall:

Ta all! Think I'm roughly on the right track then!
In terms of the safety aspect, we have a load of s-glass fibre cloth lying around, absolute top dog in terms of its strength. Plus the top couple of layers will be mainly resin to prevent any stray fibres coming through.
Few reasons for using fibreglass. One we already have it. Two, all the other volumes there are made of it and three I can define the exact shape I'm after much easier in fibreglass than wood. Want some really curved edges to prevent laybacks off one edge. I'm not that good with wood you see!

Good point on the testing aspect though. I shall make some enquiries about that. I'll take a few snaps of our little project in case anyone wishes to follow in our footsteps

Benny.