This also applies to fuse boxes, connector blocks, etc.
I developed this procedure when I was with the Cotswold Aircraft restoration Group. It is effective, provided the component in question is not an "in the bin" candidate!
Broken mounting lugs are the normal damage found on these components and can be rectified by the following repair procedure.
Plasticine is used to make a mould, using a good corner of the damaged component as the master pattern.
This good corner is pressed into the Plasticine block to leave a master impression for moulding the damaged area.
The component is then carefully removed and small angled holes are drilled laterally into the damaged lug area, into which, fine copper or steel rods are inserted to reinforce the area to be moulded from the master impression. Position these reinforcing rods so that the ends do not encroach any component mounting holes.
The drill size is usually 1.5 - 2 mm, depending on the thickness of the damaged lug.
The component is then fitted into the plasticine mould with the broken section located into the master impression.
Slow-setting Araldite... (Araldite ARA400001 Precision grade is preferred)... is mixed with bakelite filings from a similarly coloured scrap piece of Bakelite, and introduced into the mould void, slightly overfilling to allow for final shaping and finishing.
The epoxy/Bakelite mix will flow more successfully if gentle heat is applied as the void is filled.
When set... allow at least 24 hours undisturbed; carefully peel the Plasticine mould away, and trim up and shape with scalpel and fine files.
Finish with a fine-grade wet and dry paper.
I developed this procedure when I was with the Cotswold Aircraft restoration Group. It is effective, provided the component in question is not an "in the bin" candidate!
Broken mounting lugs are the normal damage found on these components and can be rectified by the following repair procedure.
Plasticine is used to make a mould, using a good corner of the damaged component as the master pattern.
This good corner is pressed into the Plasticine block to leave a master impression for moulding the damaged area.
The component is then carefully removed and small angled holes are drilled laterally into the damaged lug area, into which, fine copper or steel rods are inserted to reinforce the area to be moulded from the master impression. Position these reinforcing rods so that the ends do not encroach any component mounting holes.
The drill size is usually 1.5 - 2 mm, depending on the thickness of the damaged lug.
The component is then fitted into the plasticine mould with the broken section located into the master impression.
Slow-setting Araldite... (Araldite ARA400001 Precision grade is preferred)... is mixed with bakelite filings from a similarly coloured scrap piece of Bakelite, and introduced into the mould void, slightly overfilling to allow for final shaping and finishing.
The epoxy/Bakelite mix will flow more successfully if gentle heat is applied as the void is filled.
When set... allow at least 24 hours undisturbed; carefully peel the Plasticine mould away, and trim up and shape with scalpel and fine files.
Finish with a fine-grade wet and dry paper.
