disco sills or any sills

[henryandlesley]

Hi now i have done the sills on my disco i was thinking about filling them with expanding foam so it stops the water from getting back in and rotting them out away has anyone done it before

[Disco Matt]

It's a neat idea, I'd just be worried about whether the foam had filled every inch of the sills and whether it was trapping water inside them. There's also the problem that if you needed to weld them again then you'd have to remove a load of foam to avoid setting fire to the truck!  :lol:

If it was possible I'd suggest constructing the sills as airtight boxes and filling them with nitrogen, which is inert and would not allow rust to take hold. It might however make you a bit more likely to float away in deep puddles...

[Disco-Ron]

Mids 70's classic mini;'s had their sills filled with foam....... i wouldn't bother if i were you, it's crap... i suggest that it would just get wet, and stay wet forever, makiing the situation even worse.....

[Range Rover Blues]

Agreed, it makes it worse.  Waxoil or zinc rich paint ;)

[lee celtic]

I'm About to do the box section thing with mine I was thinking of the foam thing but then thought I would seal the ends of the box section with steel plates but with a nut welded on one end so I can stick a load of wax oil in then put a bolt to close the hole afterwards then as I drive around it will recoat the insides  :lol: :lol:

I can then top it up when needed  :dance:

Might do something similar on the rear cross member  :-k

[waveydavey]

It is probably expensive but you could try specifically anodes inside? Basically weld a block of zinc (yes I know it doesn't weld, you get it cast onto a steel bar) inside so that if it gets moisture that corrodes instead of the steel ; that is basically what galvanising is anyway.

[V8MoneyPit]

Mids 70's classic mini;'s had their sills filled with foam.......

Not quite true, but not far off. Extremely early Mini's had foam filled sills (from 1959 to 1960 or 61 at the latest). Then, when they found it held water more than it stopped, they left it out. Then the water drained into the floor instead, so they redesigned the sills from 1963 onwards.

Anyway, filling sills with foam is a bad idea!!

[Drift]

Ive heard this but not done it, run used engine oil through the inside your sills make sure it coats all the inside, so fill them then drain, will leave a nice oily coating to protect them.

[barnhill4x4]

My grandad had a vauxhall firenza from new, every oil change he would spray the underside with oil. He then sold it (without me knowing as I wanted it!) about 5 years ago, the guy that bought it steam cleaned the underside and it was still factory white with no rust!