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OT Acrylic sealant query

Problem: Client of the charity I work for who is working for London Underground has 'safety' shoes with a hollow grid supporting the heel, the inner sole or liner deforms over time so the grid digs in and damages the heel, however the shoes do protect against high voltages. Possible solutions include cutting blocks from wooden strip (available at most model shops) and fitting thiese in the voids but that'd be a bit fiddly and I am not sure they could cut them accurately enough to avoid causing problems with raised blocks. I'm in Manchester, 200 miles away, and hence cannot 'pop round' to do the job. I happen to have a pair of very cheap 'shoes' to hand which I was throwing out because of the exact same defect in design, I also have a tube of acrylic sealant, considering trying squirting same into voids, quoted curing time 48 hrs. However I gather this is not waterproof even when cured (cures by evaporation of water) and hence not sure if this is a good idea inside a shoe. Also concerned that the quater inch deep rectangular voids would function pretty much as the tube does and the stuff wouldn't cure, just form a thick upper skin. On the plus side its just a question of peeling back the inner liner and squirting in the goo until it is slightly proud of the top of the grid, then leave open until cured before replacing the liner. Anyone know anything about this kind of stuff, I normally use silicone, bought this stuff at the local 'pound shop' as I was making a model farm for a kiddie and the acrylic type can be painted. Hence it'll be cheap, low modulus with a lot of chalk in it (but it is a handy scenic modelling material). Any thought/suggestions welcome.

Regards

Mike

Reply to
Mike Smith
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My advice: Do NOT attempt to fill the hollow grid with anything. It's a piece of safety equipment, and altering it might compromise the protection. Some nonconductive substances aren't effective at high voltages, or under certain conditions such as when wet.

It *might* be okay to insert a sheet of stiff plastic on top of the grid, but I wouldn't want to bet my own life on it.

Acrylic or silicone sealers would just form a thick skin, and the stuff underneath could stay gooey for weeks or months.

If the shoes won't be used for high-voltage protection, I'd just cut new insoles out of a stiff material like polyethylene from a milk jug, and add padded insoles for comfort.

Reply to
Wayne C. Morris

Thanks for the reply - The person in question works in an office, so the electrical protection is not (hopefully) an issue. Think you are right about adding some kind of cover though, have been trying various filler type materials in short lengths of tube and I am getting a lot that do not fully cure as you suggest (the ones that set solid are rather expensive to boot). The acrylic sealant sets by evaporation of water, and apparently doesn't take too well to damp conditions, so that's out (still handy as a scenic material though). I had tried using pretty solid insoles taken from another pair of old shoes on the ones I am throwing, this worked for a bit but over time they deformed over the ribs. Personally I will avoid this kind of heel in the future but it's handy for these experiments. Might try cutting some sheet metal from an old computer case, we have some old units with comparatively thick cases (and I doubt we will find a use for old 486's these days).

Thanks again for taking time to reply, I'll double check the electrical safety issue.

Just got a kit I have wanted for years, or rather have wanted to kit bash for years, so my patience with this job may wear a little thin if I do not solve it in the next couple of days.

Regards

Mike

Reply to
Mike Smith

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