Subframe rust prevention

[jasst]

As most of us know, the subframes on these can rust, and usually from the inside out. Now mine is in not bad condition on the outside, I have treated any small areas of surface rust there were, but I am more concerned about what may be happening on the inside, so I was thinking weather it would be deemed sensible to drill a small access hole so that the interior could be injected with waxoyl, or some other similar product to protect the inside. I am initially thinking about through the end plate on the main oval shaped tube, Thoughts gentlemen please.

 

[davy83]

This is a tricky question. If the subframe structure is sealed and the air inside the subframe is not in connection with the outside world, your access hole will allow moisture and all sorts to get into your clean dry subframe interior. On the other hand it does provide you with some level of comfort as you could use a small endoscope and inspect the inside. This is indeed a quandary.
I have just treated the outside of my subframes at least once a year, and give them a general clean up. i have often thought about drilling a hole and faced this exact question. I would be interested in any responses. I know that owners who have found their subframes rotten are usually shocked and recommend everyone checks the condition regularly. I had a TVR that rotted through and had to refurbish the whole subframe to fix it, that was traumatic!!

 

[mjheathcote]

A drilled hole can always be plugged afterwards with a plastic or rubber plug. Sounds a good idea to me.

 

[lifes2short]

yep defo drill and inject, bilt hamber do some good products both for cavities/box sections and underside, if you don't have a compressor they also do large spray cans with the flexible cavity lance

 

[lifes2short]

this stuff

Bilt Hamber Dynax S50 Extreme Anti-Corrosion Wax for Cavities 750ml With Lance | eBay

The cavity wax chosen must cope with all these variables and continue to provide the necessary protection – maintaining the structural integrity, safety, and value of the vehicle. Supplied with one 600mm injection lance per aerosol.

www.ebay.co.uk

 

[philw696]

A drilled hole can always be plugged afterwards with a plastic or rubber plug. Sounds a good idea to me.

Just like the likes of Ziebart used to do.
My old XJC was treated.

 

[midlifecrisis]

I think and I''m open to correction that the subframe is made up of various tubes and therefore there's multiple cavities. You'd have to drill multiple holes for the muliple cavities. I think a few 4200/GS sub-frames corroded worse by the suspension mounts on the drivers' side.

 

[Soenvious]

Just like the likes of Ziebart used to do.
My old XJC was treated.

I had a TR7 that had been Ziebarted......it only rusted on the bits of metal where the Ziebart didn't reach, basically all over

 

[philw696]

I had a TR7 that had been Ziebarted......it only rusted on the bits of metal where the Ziebart didn't reach, basically all over

My car survived quite well indeed and in my ownership in New Zealand I gave it a good injection of fish oil which is very popular that side of the world through said plug holes.
Excess did leave some staining on the driveway though.

 

[CatmanV2]

I had a TR7 that had been Ziebarted......it only rusted on the bits of metal where the Ziebart didn't reach, basically all over

Our first 116 Giulietta (Old V plate) was Ziebarted from new. So it took 6 weeks to rust, as opposed to the 2 weeks of the un-treated ones

C

 

[HenrysDad]

I Ziebarted a 1983 Lancia HPE. (my best car ever!) It had multiple issues but didn't' rust at all. I sold it in 1991 so I am a fan of the process. I too worry about my subframe and get it checked every yr (only one so far!).

 

[Scaf]

I had my GTS and then my Strad protected at Sportsitalia but do not know if that involved internal injection.

 

[Gazcw]

I had my GTS and then my Strad protected at Sportsitalia but do not know if that involved internal injection.

That just sounds wrong. Was it a big bill?

 

[conaero]

I had my GTS and then my Strad protected at Sportsitalia but do not know if that involved internal injection.

We get in where we can but the topic here is the 4200 tubular subframe which does rust from the inside out whereas the GT/QP rusts from the outside in.

There is one box section low down and transverse that does and it’s open at each end so we flood it as best we can.