MK1 sill rust prevention and causes

[08SWB-connectOwner]

Hello.

I will be replacing the sills on my 08 SWB, to both repair and check for rust.
The other sill was already 'repaired' by the previous owner, less then a year ago.
I checked with an endoscope, and there's already plenty of moisture in there!

As I understand it, the rusting is caused by poor design, which lets moisture, namely condensation into the sills.
Since I'm making these repairs, I thought I might as well do what I can to prevent, or at least mitigate rust in the future.

Are there any specific modifications that could help to achieve this, beyond the usual cavity waxin etc?

Couldn't find a dedicated topic for this, or clear directions etc.
So I thought might as well gather this information for everyone else to find as well

Thanks!

[metalworker0]

All the sill section panels are made of 22 gauge steel , which is a very thin - 0.7mm that does not help.
Instead of making inner and outer sills out of much thicker metal ..Ford made a sandwich of inner, muddle and outer ..all out of this 0.7mm metal.
They added rust traps .and place for the water to get in, there are drains , but There are also a row of holes running along the entire sill...these are not drainage holes ..as they let water in .
see how this replica sill manufacturer has replicated the mistakes . see the row of holes.
https://i.ebayimg.com/images/g/xfkAAOSw ... s-l960.jpg


Behind each front wheel just where the wheel arch liner stops ..there is another hole to let water in strait off the wheel.

Construction details: last picture - the red region is where it rots the most... as you can see lots hidden boxes and what nots, that you cant see when you attempt to waxoyl it .

These sections have to be noted when you have it apart ..and during sill repair you have to make access possible by drilling holes and closing them with grommets, ready in place for the cavity wax.

any water that gets into the outer sill has to go through the slots in the second picture and drain out through the the swages in the inner sill, in the first picture.

[metalworker0]

Part 2 . Because of capillary action some water that is in the bottom of the sills stays in the the three panels pinch zone that are spot welded together, (the bit hanging down in the last picture) , the water sits in this sandwich for long periods of time , the British climate is very humid ..condensation in the panels happens often ,, so the sandwich is always being fed...results in swelling ..lots of layers of porous rust , that accelerates the process.

How to make your repairs last a bit longer

1.Use weld through primer

2. Pour in paint ..see pics below, red arrows are blue tack, Once all the panels are in place and welded up lay down some DPM sheets.....block all the drainage holes up with ..putty ..blue tack ..or what ever you can get your hands on , then fill the sills with about a pint of paint ...primer , house hold gloss ..what ever you can get your hands on - if you can get hold of red lead ..last made in the 70's ..this will be best. leave for half hour or so ..so that the paint penetrates the sandwich ,,, take the putty off and let it drain.

3. Waxoyl,
Note: waxoyle when used even warm will solidify when it hits a cold steel surface ..so to give it a chance to penetrate, follow below.
You want the waxoyle to penetrate every nuck, cranny and seam ..to do this the waxoyle has to be warm or even hot, so only do it in the high summer ..on the hottest day, if using air fed sprayer.
The shultz guns are garbage for this task and you should buy the Sealey one ...run the airline through a 5 gallon drum of boiling water ...or make a mini bore copper pipe up and immerse in drum. also heat up the waxoyle in bucket of boiling water.

4. The hidden box sections are important , these need waxoyle. if you don't do them then you may as well not do it at all .will be a waist of money.

all the best.mark

[08SWB-connectOwner]

Awesome reply!
Thank you!

Could I pour the wax in the same way as the paint (in step 2), and then use a heat gun to heat up the sill a bit, so that the wax stays warm as it spreads more like a fluid?
I understand this will require alot more wax, but the Sealey wax injector seems to be quite expensive. It'll be cheaper to buy litres of wax.
Maybe I could use the cheaper gun first, to get the wax all over the insides, and then pour in the wax?

[metalworker0]

if you pour wax in, i suggest you mix it with machine oil / hydraulic oil ..as it will set and block the drainage holes up "as is " even when hot. 50/50 mix will get it to penetrate ..then leave a couple of months and then do the normal spray job.

The sealey gun is about £120 with a gallon of waxoyl
The waxoyl gun, the hand pump - their own make, isn't that bad .and less likley to cool the wax down like the air version

Don't forget , there are other products like lanogaurd or Dinitrol

my thread on putting the sills on is here .

viewtopic.php?f=54&t=209329&start=30

all the best.mark

[Altransit]

my thread on putting the sills on is here .

viewtopic.php?f=54&t=209329&start=30

I've made that topic a stickey, so it should be easier to find.

[metalworker0]

IMPORTANT - when repairing inner sill ...note the depression in the inner sill, its there to facilitate getting the spring hanger bolt out.

if you cant replicate this ...suggest pulling bolt out and turning the other way around ..or you'll never get it out in the future!


all the best.mark

[08SWB-connectOwner]

UPDATE.


Right.

Last week I ordered new sills (stamped) and supplies. I expect them to arrive sometime next week.
I was only able to get 1.5mm thick sheet for the structural bits. I hope that's enough thick?

[metalworker0]

well it may be a bit thick to work with and manipulate ..but you'll n be happy with the results as they will be stronger and longer lived than original.

the sheet i got for mine was a bit "out" it was probably 1.5mm at one end and 1.2mm at the other end .

1.2mm would have been ideal

all the best.mark

[08SWB-connectOwner]

Started, left side (the better side).

While not a complete disaster, in fact mostly expected, there is plenty of work to be done.
The middle sill needs to be replaced and at least the rear part of the inner sill too.
I'll have to cut it out anyway to replace the middle sill.
But I'd like to maintain as much original steel as possible, as I just lack the equipment and money to do bigger repairs. So if the condition of the steel is passable, it'll get welded back.

Ideally I'd replace any and all pieces of contaminated metal. But if it has just some surface rust, It'll have to do. It's the best I can do right now.
I'll just have to get the rust off and repaint the metal. Of course, if it has more than surface rust, it's going to get replaced. I'll just have to make do with the rest.
Hopefully I'll be able to see with a bore camera how high the rusting goes.The higher it goes, the higher I need to make my cuts and the harder it becomes to protect the metal from the other side, once welds are laid on.

imadge.png

Rear:

imsage.png

Front:

iamage.png

Middle sill.

nimetön.jpg

For the most part, it's just surface rust. But it will still have to be replaced.


The right side is much much worse with some really shoddy snot weld repairs done by the previous owner just to pass inspection.
However, I reckon I'll have to ultimately do pretty much the same amount of work and repairs on both sides.

It's midsummer celebrations time now.

[metalworker0]

not as bad as mine was ..
weird ..i have to ..either open each picture in new tab to see your full pictures or reduce the magnifier down on my browser to 50 percent to see full pics.

anyway looks like you have not got as much work ..well looks like from pics ..unless you then start screw-drivering it to see how weak it is .

the worst on mine was at the back of the rear of the sills

all the best.mark

[08SWB-connectOwner]

not as bad as mine was ..
weird ..i have to ..either open each picture in new tab to see your full pictures...

It's probably because I used an external host and linked them here. This site then has to resize them, because they're not the 'correct' size.
I'll see if I can fix the issue.

EDIT: Should be good now.

[08SWB-connectOwner]

UPDATE TIME:
(no pictures however)

There is plenty of surface rust, rising a bit higher a the middle and at the rear end, but luckily the inner sill is good for reuse for about 3/4 of its length.

The rust on the middle sill rises quite a bit higher and it will need to be replaced.

However, this presents a problem:
The rust reaches a spot in the construction, where they've made a bulge into the metal. I cannot fabricate this bulge, and cutting above it impossible, without cutting more of the inner sill off, which would defeat the purpose of keeping the old metal as I would need to lay on two seams of weld to put it back.

Therefore, I will settle for a compromise:
I will overlap the new metal with the old metal.

I will cut where the middle sill meets the chassis box, remove as much rust as possible, put on etch-weld primer and weld the new metal partially over the old metal.
Not optimal, especially for preventing rust in the future, but it should work just fine otherwise. Should be structurally good enough, as it is just a flat bit of relatively thin sheet (the new metal is thicker than the original from the factory), and the van itself will likely come to the end of its life before rust defeats the repairs.
I reckon this car has 10 years left at maximum, being already at drinking age (16). (side note, it's actually in a really decent condition with really low miles, it's just the sills that are shite)

At the rear end, however, the rust rises very high, to a point where the metal bends away from sight. I don't know what I'll do to it, yet, or even how bad it exactly is. I quit today once I got the inner sill off.
Tomorrow I'll have a better look at it, once I've spent the night crying.
There's plenty of odd bends and shapes at the rear and I'm a bit scared, especially when given the limited tools and resources I have available.
But I'll figure out something that'll work well enough, I'm sure.

[metalworker0]

I think these pictures are of the other side that i did first, back of rear inner sill.. as you can see it was bad ...note the original strengthener that is there for the jacking point ....i did away with that and just used a 10" x 3" x 1/4" bar of metal as the middle sill in that region ..
Also note, i did not copy what ford did ..and just made it stronger than it was ..not even looking the same does not matter as its not on show, all that matters is its strength when jacking and general solidness to the MOT guy...note the gap for the spring hanger bolt to come out .

[08SWB-connectOwner]

I did not copy what ford did..

Yes, I'm likely also making it as simple as possible whilst maintaining (at minimum) a level of strength equal to factory spec.
I have a few pieces of 2mm steel, but I'm not sure if that's enough for both sides.
By the laws of my MOT, the inspection officer will want both sides to be equal in construction if totally replaced or rebuilt.
This also means they can't look too far off of how they originally looked, so I can't just make them completely flat.
Regs say they would have to be exactly how they were made in the factory, but luckily the officers have a brain and will allow repairs that have been done sufficiently well.

Also, luckily I can hide some stuff with a generous application stonechip

I'll make a more detailed plan tomorrow.