Hi all
I’m new to the west midlands owners club. I’ve just had a recent MOT on my MX5 2.5 2003 and the advisories showed quite a bit of rust on the chassis.
I am looking for methods of preparing the chassis before resealing / wax oil / painting to prevent the spread of rust.
Any top tips would be great. (soda blast, shot blast) and does anyone know anywhere in staffordshire that does ramp hire?
Thanks in advance
You will find that some of the original stonechip underseal is no longer sticking to the underside of the car. In these cases remove the stuff that is hanging off and then check the rest and take off any underseal that is holding water or not sticking well to the underbody and do not think, that will be fine there is too much to remove, try to remove all underseal and only leave on that that is still sticking to the steel.
I am advised that you should use aluminium based abrasives to remove rust to clean metal but there will still be some rust pits there, not an expert on abrasives.
I would use a rust passivator like Bilthamber 80 but your choice on the one you use.
If you have the time I would also prime the surface after that according to the paint manufacturers instruction.
Then your choice of goo. Either a stonechip that is a better sound insulator and far better in exposed wheel arches. Or an underbody wax on the underside not in exposed wheel arches. The wax tends to need topped up sooner than the stonechip.
For cavities and wheel arches that are protected by liners use a cavity wax like Bilthamber Dynax S50 which they claim has a rust preventer in it but on an MX5 as they tend to rust from the inside out, you will not realy kill the rust already inside the rear sills and wheel arches and the front chassis rails.
No amount of underside goo will stop very rusty steel rusting through, therfore assume some metal needing replaced.
You must remove the engine undertray and hammer the front chassis rails and hit them hard to make sure they have not failed. For the avoidance of doubt it is just stupid not to hit as hard as you can as they are a safety item, in a crash and should not be left because they look OK and you cannot afford to repair them just now.
In a shared garage blasting will in most cases cover other kit in the garage so that may well be a non starter unless you have a facility that has no other cars in there.
Any bad rust or perforation in the rear sills is also a saftey issue and just filling with filler is again very unsafe. If there is any perforation the steel must be replaced.
Hi
Covering rust with “goo” will not stop it progressing, but will make it much harder to weld & repair when the time comes,
and that time will come.
Paul G
You have to ask yourself if a car like that maybe worth a few hundred pounds is worth spending money on,the tin worm has set in and smearing goo will achieve nothing.