How to protect your new subframe from rust?

[lamcote]

Thanks, do you know what it's made of?

Also does anyone know if you can wrap the flexis on the exhaust?

[Carolyn]

It's a steel bellows inside the mesh covering, with steel mesh on the inside of that.  If the rest of the exhaust is wrapped, it will still be pretty much as hot as the rest of the exhaust.  Mine aren't wrapped, but (thinking about it) I can't see it doing that much harm.  Having said that, the flexis are often the first part of the cat pipe to give up and leak....

[lamcote]

Hmm, on balance maybe not the best idea?

I like the idea of some sort of heat shield though.

[Carolyn]

The most effective heat shields have an air gap between the shield and the shielded item.

[lamcote]

So should it be connected to the exhaust and not the sub frame or does that not really matter?

[Bernie]

Thanks, do you know what it's made of?

Also does anyone know if you can wrap the flexis on the exhaust?

Just heard from Rob its this

 m http://www.demon-tweeks.co.uk/performan ... -barrier-2 m

Held in place with riveted aluminium strips


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[lamcote]

Thanks that's very helpful, looks impressive stuff.

[Carolyn]

This on Spyder chat from 'Key Techniques':

"There can be corrosion issues with northeast cars that see frequent snow but there is something with the UK weather that has caused my customers grief with my Energy suspension install where the old bushings were corroded on the control arm.
This was not the case in North America as even my Canadian customers had no issues.
There were no issues either in Spain, Germany and the eastern regions. No issues in Asia as a whole."

The mystery deepens, but it tends to confirm that British road filth needs to be kept out.

[1979scotte]

This on Spyder chat from 'Key Techniques':

"There can be corrosion issues with northeast cars that see frequent snow but there is something with the UK weather that has caused my customers grief with my Energy suspension install where the old bushings were corroded on the control arm.
This was not the case in North America as even my Canadian customers had no issues.
There were no issues either in Spain, Germany and the eastern regions. No issues in Asia as a whole."

The mystery deepens, but it tends to confirm that British road filth needs to be kept out.

Thats Dev who does the keyhole cover and de dimplators.
He knows what he talking about.

[Carolyn]

Done some more research.  Our road 'grit' contains Cheshire rock-salt.  While mostly common salt (Sodium Chloride) this contains varieties of 'Potash'.  'Potash is a catch-all term for potassium salts, some of which are quite corrosive.  Potash miners use stainless steel tools and equipment because it corrodes steel at some rate.

[lamcote]

Well done, very useful, I tend to agree that sealing up those top corners is the way to go.

Makes you wonder what damage is being done by all this salt, surely making winter tyres compulsory would be a better option?

[Bodgeroo]

Rustbuster epoxy mastic 121 on the outside.
The latter won Classic Car magazine best that protection product a couple of years back.

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Just a quick thanks for this post. I have now painted up my subframe with this stuff and it's truly superb! Great recommendation! Once cured it's really tough! Well recommended.

If anyone's interested it was purchased from
 m http://Www.rust.co.uk m
Crap website but ace product!

[ferry]

As a newie looking at buying a facelift MR, the cross member has become my primary concern, which has led me to a number of threads, including this one.

Would it be possible to illustrate some of the points being made? I think people are homing in on an ideal recipe for prolonging the life of the part, it would be good to have a simple guide for people to follow.

i.e. seal here, bung here, spray this here, paint that there etc.

[The Other Stu]

So, sealing the top corners would seem to make sense as that's where real road filth can get in.  The drain holes should allow for adequate ventilation.  Anyway, that's my theory so far - and now we seem to be accumulating evidence, rather than opinion.

Following our discussion, that's exactly what I've done.
The holes in the top/side are a nightmare. Think about it, the wheels are throwing up water in exactly that area. Those holes are huge and are going to let in loads of it.
I couldn't decide what to fill mine with, so used gun gum and primed. If it's good enough to seal an exhaust permanently, it should be plenty good enough to keep the water out! Another suggestion was engine sealant.
Treated mine entirely with red oxide primer, then hammerite anti-rust, then a liberal coating of waxoyl underbody coating. Waxoyld inside too.

It's probably the one part of the car I'm not going to worry too much about for a while.

[ptennisnet]

I've often wondered about high temperature expanding foam.  To be fair, I've not been brave enough to do it.  I've dynaxed the inside but will take a look at sealing the holes as described in this thread before next winter.  Mine's my daily driver, so is exposed to the worst of winter, including being stuck behind a gritter for miles on the country lanes a couple of times last winter

[JoeCool]

As a newie looking at buying a facelift MR, the cross member has become my primary concern, which has led me to a number of threads, including this one.

Would it be possible to illustrate some of the points being made? I think people are homing in on an ideal recipe for prolonging the life of the part, it would be good to have a simple guide for people to follow.

i.e. seal here, bung here, spray this here, paint that there etc.

Tehre isn't really any consensus on 'the best' option yet. Sadly no-one really ahs the ability to properly test what method is optimum.

But in short:

1) Buy a car with a solid sub frame, so it's not an immediate concern. You need to pull the rear under tra off to insect it fully. See this thread for reference to where they fail ad how. Note it's the underside that goes, where the suspension arms join it.

2) If your sub frame is good, protect it. Paint the outside, put some kind of rust protection on the inside.

3) Keep a close eye on it.

4) If it's not good, start sourcing a replacement, be it a new one from Toymota (£300) or a good second hand one (there are breakers who will sort you out).

[SombreroPeak]

How easy (or not) would it be to paint /treat it in situ?

I had a new one fitted last year by Steve at D1, he treated in inside and out, but obviously worth keeping an eye on it.

[The Other Stu]

The underneath is easy enough with the nappy off. Some of the top can be done and arguably, you could waxoyl the inside if you're happy that it's dry.
But the danger bits, i.e. the edge gaps, not so much.

[Bossworld]

So, sealing the top corners would seem to make sense as that's where real road filth can get in.  The drain holes should allow for adequate ventilation.  Anyway, that's my theory so far - and now we seem to be accumulating evidence, rather than opinion.

Following our discussion, that's exactly what I've done.
The holes in the top/side are a nightmare. Think about it, the wheels are throwing up water in exactly that area. Those holes are huge and are going to let in loads of it.
I couldn't decide what to fill mine with, so used gun gum and primed. If it's good enough to seal an exhaust permanently, it should be plenty good enough to keep the water out! Another suggestion was engine sealant.
Treated mine entirely with red oxide primer, then hammerite anti-rust, then a liberal coating of waxoyl underbody coating. Waxoyld inside too.

It's probably the one part of the car I'm not going to worry too much about for a while.

Do the gaps allow for any form of drainage? To be honest I'm not sure if all the original rubber bungs made it back onto my replacement, but it's had two decent coats of hammerite and a cavity waxing.

I gave up on science after GCSEs but just wondering if there would be any acceleration of interior rust if it's not got some manner of ability to 'breathe', for lack of a better term, given it's hollow?

[The Other Stu]

The side gaps are at the top. The water should drain through the bottom in the middle, where the bungs are.
But what happens in reality is that you park it slightly not on the flat, and the water all gathers in one of the bottom corners rather than going out through the bungs.

[MisterK]

Just to put this in perspective, my car is 13 years old on Sunday.....taaaraaaa!   s:bounce: :bounce: s:bounce:  

The subframe is still the original from new.  About 5/6 years ago the rotting subframe issue came to light so I used rust treatment on the rust spots on the outside that I could get at, and then sprayed the outside with Dinitrol, took the bungs out from the top & gave the interior a good coating of Dinitrol too. All bungs were then replaced, but nothing else was done. I

Last year I decided to invest in a new subframe from Mr T. to ensure I've got one available, when & if the time arrises   s:D s:D   This has been treated to Hammerite on the outside, the weld gaps have been sealed with black Tiger Seal and the inside treated with Dinitrol.  This is now sitting in my garage but it is not on the car   s:shock: :shock: s:shock:  

A couple of months ago I was with Steve at D1 Customs and we checked out the original subframe whilst the car was up on the ramp.  Would you believe not a spec of rust and it looked like new.  It was then sprayed with underseal and left in situ....it should last for many years to come, hopefully   s:wink: :wink: s:wink:  

So the moral of the story is, a fully treated subframe should last for many years and could probably outlive the life of the car   s:D s:D

Bye the way, the car passed its MOT yesterday and the Toyota Technician (that's the posh term) advised me that Mr T do now check subframes for rust - maybe a back street MOT station won't bother.

[The Other Stu]

Mr T might, but your regular MOT bloke a) isn't going to know to look for it and b) the nappy hid mine.
Genuinely, look where the nappy is and the holes appear. It's almost impossible to see without removing the nappy!

I checked mine as well as I could when I bought it, but it was only removing the nappy and getting it up on a lift that we actually spotted where the huge hole was!

[MisterK]

Mr T might, but your regular MOT bloke a) isn't going to know to look for it and b) the nappy hid mine.
Genuinely, look where the nappy is and the holes appear. It's almost impossible to see without removing the nappy!

I checked mine as well as I could when I bought it, but it was only removing the nappy and getting it up on a lift that we actually spotted where the huge hole was!

Exactly, that's why I mentioned it   s:wink: :wink: s:wink:    & yes the only thorough way of checking is from underneath with all plastics removed & that's why I was so pleased when mine was revealed in all its glory on Steve's ramp   s:D s:D

[delhusband]

Picking up new subframe today (& arb and drop links). From this thread, I'm going to go with Rustbuster epoxy mastic 121 outside and dynax s50 inside (if I can find/get them). Any advice on whether or not there would be any preparation before treating, if it's a brand new part?  (cleaning, degreasing, something else?), and any other comments or recommendations about treatment products?

[lamcote]

Good question. The subframes from Toyota now seem to come painted black. Is it possible to rust proof over the top of this paint? I assume this is a new thing? If so, do you treat it differently to the older silver ones?