28 replies to this topic

[adammini]

Yea it was very strange.

I was using the thermotec stuff that you can buy from minispares. I think other factors that could have helped the first one rot could be that in the year I had it on, the mini wasnt used much (I was at uni) but it was stored in a garage.

The stainless one cracked because of the heat that the wrap reflected back. Then with the cycles of heating and cooling it cracked on one of the welds.
The maniflow guy mentioned that this cycle 'brought the carbon to the surface' although I didnt really get what he meant. It did look different, it was all blackened and rough, not at all like stainless!

[miniboo]

I have heard of manifolds cracking and rusting aswell.

[Big_Adam]

hmmmm.......this has turned into a good debate hasn't it.

[my mini rulez]

ill be intrested to see these pics

[adammini]

Sure, here they are -

[Mephiston]

sorry to open this up again, so is it basicly a bad idea to wrap an lcb ?

so if that is a bad idea, is something like spraying an exhaust with thermo paint, a good idea or will this have the same effect ?

[Danny Boy]

ive been told the exausht wrap will trap mositure however wouldnt the heat of the exausht evaporate the water?

[I-B-Quick]

Glad I've read this as I was thinking of using the wrap but I don't think I'll bother now. Previous owner of mine had painted the LCB ( not sure what with) but it's all but flaked off now. Not sure any paint can really take the manifold heat.

[Se7enS1ns]

Ive seen barbeque paint used before that seems to do the job pretty nicely. Youve gotta give the manifolds a good session with the wire brush to remove the brown for the paint to adhere properly mind.

[Se7enS1ns]

Ok why did this post twice then? Odd....

Edited by Se7enS1ns, 25 September 2007 - 07:01 PM.

[mrthumb]

hmm i have a theory on why stainless cracks and why the tube has gone black. lots of carbon deposits on the side of the pipe get absorbed when the stainless is cherry red and is drawn into the steel maybe displacing the nickel in the stainless which discolours it and allows rust to form. nickel is what makes stainless steel stainless (mostley)... when you weld stainless, and you do it too hot, sometimes the nickel seperates from the steel and rust forms on the welds this is called nickel migration.

you see, to make iron hard we add carbon. very hard steel (high carbon) has about 1% carbon. and any more and it becomes brittle. all these cycles of heating and absorbing carbon and reheating has impregnated too much carbon in the steel and thus has weakened it permantley.

i guess the only solution is to keep the pipe as cool as possible which means not using heat wrap!
im not qualified in anything, just work with metals for a living and made some observations. hope this makes sense and is near correct!

Edited by mrthumb, 26 June 2012 - 09:37 PM.

[Alex_B]

Holy thread revival batman!

[mrthumb]

haha i never realised!

[dklawson]

Lazarus comes to mind. This has got to be an epic record in thread revival.