Some of the ABS flutes supporting a threaded brass collar had broken away forcing the collar out of alignment between the two cowls and supporting frame.old chopping boarda couple of old Lego bricks courtesy of No.1 sonside cutters and a junior hacksaw to chop the Legonail polish remover (acetone) courtesy of Mrs Art
small melting pot with lid courtesy of Wilkes & Sons6" nail to prod and poke around to see how the melt down is progressinga piece of scratchsolvent cement as used for bonding ABS and PVC plastic plumbing waste fittings
The method
Chop the Lego bricks into small pieces, place in melting pot, pour in sufficient nail polish remover to cover the Lego pieces and wait. Prod and poke from time to time to check progress, when the Lego has melted down into a soft putty like consistency its ready. I left the pot overnight, don’t worry it won’t over cook.Roughen the surface of the ABS panel where you want the Lego to bond to with a fine grade of scratch, emery paper, wet n dry anything that’ll provide a key for the bonding.Clean the area with nail polish remover and apply a light coat of solvent cement and leave for a couple of seconds then apply the Lego putty and mould to shape as required. I used a pair of flat bladed screwdrivers to do the moulding, dipping them into the nail polish remover every now again. Leave to dry.
One side sorted the other failed. Seems the Lego lost some of its strength between the melting down and drying out process. Why one side set solid and the other the other failed will remain one of the mysteries of the universe.
Nail glue, also referred to as screw glue, is strictly for puncture repairs and finger nails.
I used yellow Lego bricks so I could keep an eye on what was melting or dissolving during the application on to a silver/grey cowl
Yes the nail polish remover was acetone.
The first application worked the second didn’t :ermm:
Conclusion - Further experimentation has revealed that I may have over done the application of solvent cement. The idea of the solvent cement was to give a good bond between the Lego and fairing cowl and needs to be applied very sparingly. Too much solvent cement appears to have resulted in the Lego putty and the brass collar supporting lugs of the cowl drying out into a pliable rubber like substance rather than a solid mass.
A temporary fix has now been effected by means of a number plate nut and bolt until I get a roundtuit…
I’ve never used acetone for a fairing repair but in guitar building we use it to meld ABS plastic binding onto wood.
This sort of thing:
It works exceptionally well and you don’t need any type of cement to activate it.
You just put acetone on the binding, leave it for a min or so and then tape it to the binding channel with binding tape.
It cleans up beautifully.
I’m wondering if you could just use acetone to apply the softened lego brick material to the fairing?
I might see if I can attempt it over the next few days- I don’t have a spare bit of ABS fairing at the moment but I can probably get a piece of pipe from somewhere.
