Small repairs to undercarriage needed

[Guest]

Hello, I'm new to the Forum, having recently bought a 1988 944 Lux, 2.5 8v (Guards Red) advertised on Pistonheads. I've owned a 924S for the last 4 years as a PCGB member. Found the Forum very useful and have checked threads back over the last few months to see if this subject is covered; havn't seen it.

There is some slight damage to the underseal of the 944 in 2 places:-

1. Behind the n/s front wheel well (did the damage myself last week - don't ask[]) and

2. Near the spare wheel well at the back (rubbery underseal here, as opposed to the hard, cardboard consistency further forward) where the car has had a minor shunt in the past.

Once I have peeled back the rear underseal and rustproofed the metal underneath, can anyone tell me what the rubbery underseal is and how I can get hold of it to do a decent repair please? Similarly, what is the hard cardboard-like substance further forward and can I find that anywhere too?

I picked up a small tin of Waxoyl Underseal this afternoon, but wanted to ask before trying this. Grateful for any advice, thanks.

I've just reverted to original wheels and replaced the 18" Turbotwists with Teledials.

 

[sawood12]

If I can recall from the days I did some undersealing on an Escort you don't need to carry out any rust preventive action before applying the underseal as the underseal iteself contains an active anti-corrosion barrier which provides continued and permenant protection so long as the underseal coat is intact - or at least the stuff I used did. I just got it from Halfords. It was just a case of wire brushing to remove any loose stuff and applying. Seemed to work fine as far as I could tell at the time.

 

[Diver944]

If it's underneath and out of sight then underseal is underseal and will soon get covered in grime anyway.

The bobbly paint along the outer sill that is then painted body colour is a product from Wurth called HKS Stoneguard and needs to be sprayed on using a Shutz gun at low pressure to replicate the 'bobblyness' - technical term

 

[Guest]

Porsche used a PVC based underseal in places like the wheel arches and underneath. When scraped off it has a sort of beige colour (under the body colour).
It is tough old stuff - but not perfect. Rust will spread underneath it if given half a chance.
Rather more serious is that it burns rather well.
My 924, in the hands of a PO, had a minor electrical fire start under the servo area. It set fire to the PVC underseal on the inner wing and outer wing.

Not very practical to remove it but I do wonder if modern factory underseals are now fire retardent?

 

[cococola]

Wow that could have been much worse[]did you get the car back to normal condition?

 

[Guest]

ORIGINAL: Diver944


The bobbly paint along the outer sill that is then painted body colour is a product from Wurth called HKS Stoneguard and needs to be sprayed on using a Shutz gun at low pressure to replicate the 'bobblyness' - technical term

I love the technical term " bobblyness" LOL. Here are some pics from when I painted my car just to Ilustrate what paul has already mentioned.

 

[Guest]

Another view

 

[Neil Haughey]

Note to everyone to check the jacking points / mounts. On my car the front of the chassis rails up front have cuts in the underseal caused by many of years of supporting the car on jack stands. Luckily the climate is drier down here then most of UK so when I peeled some back the other day it was a nice grey colour underneath. One area that always worries me is the rear of the chassis around the torsion tube mounts. Mine taps out as nice and solid but the underseal seems to cut and wear off anywhere where it has been applied along a seam. I can see some time in the bodyshop to make sure all these areas are puka for me. Sadly experience of other cars tells me bad paint and rust spots on panels can be fixed easilly enough. Rust in the main chassis is probably game over for most of us.

Also there is about half a dozen small chassis bungs in the rear of the car. If you pull these out it lets all the condensation etc. out ISTR peter E mentioned about this the other day, one of my rear bins had about a cup full of water sat in it last winter. I have yet to put these bungs in but I will because a stone chipping the hole will cause the hole to start rusting.

 

[Guest]

Hello Alan / cococola
I actually bought the car as a non-runner on fleabay.
Will give some details tomorrow, meanwhile .......

 

[Guest]

and a little while later .......

 

[morris944s2john]

I would not use underseal as it cracks when dry and retains moisture causing more rust etc. Go to your local paint factors and get a tin of brushable seam sealer. This is perfect stuff to repair the underbody coating on the 944, its very simmilar to the original sealer used. Then from the same factors get an aerosol of primer and body colour of your car. Once the seam sealer is dry, prime, let that dry then top coat. When this is dry use Dinitrol underbody wax.

 

[Guest]

Thanks John,

That's very helpful. Andrew

 

[sawood12]

The underseal i've used in the past permenantly stay's rubbery, even after a couple of years. I thought that's what underseal was supposed to do?

 

[Alex Postan]

Careful where you buy it; many places overcharge. Daylight Rubbery.[]