Dreaded rust / tin worm (1 Viewer)

MattR

LIFE MEMBER
Aug 18, 2013
4,083
37,358
Beds
Funster No
27,578
MH
Panel van
Exp
Years
Both of our vehicles are showing signs of rust - the Mazda Bongo more extensive than the Merc. Both are nearly 20 years old.

I've cut back the worst of the rust on the Bongo and started the anti-rust treatment. The Merc has seen the side of the flappy pad from my angle grinder as I've stripped the paint back on the side of the arches facing the wheels as it was bubbling and showing rust.

I've treated some of the exposed metal with Hammerite rust removing gel - which I don't like as it leaves a thin film over the surface of the metal which I do not think is good to paint over.

The rest of the metal has been treated with Jenolite stage 1.

Hoping that I have killed the rust, should I use Hammerite anti-rust primer and then paint / spray over the top or use Jenolite stage 2 before painting? I've used Jenolite before but read some reviews recently saying that that film it puts over the metal is great for keeping damp out but it is also good for hiding rust that can develop underneath it so all looks fine until it more damage has developed.

What rust treatment do you use and what top coat do you recommend once the primer has been applied?
 

Dave K

Free Member
Mar 24, 2015
1,311
2,477
Somerset
Funster No
35,561
MH
Pilote P740C
Exp
Since 2013
I've had a couple of VW T4's in the past which always suffered with rust around the arches, only way to get rid of it is to cut it out and renew sections, depending on budget of course, anything else just seems to be temporary
 
OP
OP
MattR

MattR

LIFE MEMBER
Aug 18, 2013
4,083
37,358
Beds
Funster No
27,578
MH
Panel van
Exp
Years
I've had a couple of VW T4's in the past which always suffered with rust around the arches, only way to get rid of it is to cut it out and renew sections, depending on budget of course, anything else just seems to be temporary

It is frustrating how temporary repairs can be. I can't work out how some areas can rust without any apparent damage to the paintwork when the rear of the panel is sealed or protected from rain / spray.

It was disappointing to see how many small areas of rust were developing on the Merc but I only noticed it because I wash my vehicles by hand to help check for such deterioration.

Subscribers  do not see these advertisements

 

Dave K

Free Member
Mar 24, 2015
1,311
2,477
Somerset
Funster No
35,561
MH
Pilote P740C
Exp
Since 2013
It is frustrating how temporary repairs can be. I can't work out how some areas can rust without any apparent damage to the paintwork when the rear of the panel is sealed or protected from rain / spray.

It was disappointing to see how many small areas of rust were developing on the Merc but I only noticed it because I wash my vehicles by hand to help check for such deterioration.

I've been there myself Matt, always washed the T4's by hand and even after getting one resprayed and treated professionally it was showing signs of coming back within 12 - 18 months, as you said previously it can rust towards the inside even if you try and seal the outside, long term the only way is to cut out and replace.
 

Charlie

Free Member
May 16, 2015
3,211
3,639
Herefordshire / Worcestershire borders .
Funster No
36,385
MH
Auto Sleeper Kemerton.
Exp
Im a newbie
I think it's in the steel or the quality of the steel. We woul associate materials used in quality brands as being of a high quality but it's not always the case. If the actual steel is not great it will fail and especially in the more exposed or prone areas. I'm no metallurgist but that's maybe what it is .
 
OP
OP
MattR

MattR

LIFE MEMBER
Aug 18, 2013
4,083
37,358
Beds
Funster No
27,578
MH
Panel van
Exp
Years
I understand that road salt has become more corrosive and less refined (no longer rounded but as angular as it is mined) so not only is it more likely to cause paint damage but the corrosion is more severe.

I'll treat this again as well as I can, but keep an even closer eye on the areas treated to monitor the effectiveness of the poor ducts that I use.

Subscribers  do not see these advertisements

 
Aug 18, 2011
12,090
17,892
derbys
Funster No
17,808
MH
AUTOSLEEPER SYMBOL
Exp
since 2007.Tugger before since 1970
Mercs from 1999 to 2003 are very prone to rust,,,,cheap steel,,,BUSBY.
 
Nov 18, 2011
11,856
42,474
Planet Earth
Funster No
18,938
MH
A van
Exp
Over 25 year's
I have only ever had old vehicles so know where your coming from I cut back and patch then clean till bright with grinding
disk this gives a rugh finis treet with a zinc based primer then finish with good quality filler not the essay sand crap
I usually mix in a bit of liquid resin this helps to get a good bond with the repair then use a high build primer then top coat
I then treat any areas with a mix of under seal and wax oil
Bill
 

ambulancekidd

Funster
Sep 23, 2014
10,298
28,339
Ayrshire Scotland
Funster No
33,478
MH
Swift Kon-Tiki 640
Exp
Since 1964 Gosh that makes me feel old.
When our old Bongo was professionally treated for rust & resprayed, our coach builder informed us that rust tends to start from the inside. So he treated both sides of the metal & we never saw rust on the old girl again. The old girl was white & I always feel that white rusts or at least shows rust before other colours would.s with interest. Our current vehicle which is a Sprinter is beginning to show signs of the dreaded tin worm where there are a few stone chips, so I'll keep watching your post

Here is the after photo, sorry didn't have before photo.

Subscribers  do not see these advertisements

 
Last edited:
  • Like
Reactions: Geo

Geo

Trader - Funster
Jul 29, 2007
11,757
14,563
Mansfield,Notts
Funster No
35
MH
Autotrail Tracker FB
Exp
45 +years with breaks
Rust a comprehensive lesson
As a guy who cut his teeth on welding and vehicle restoration Ill give you free of charge the benefit of my many years experience, provided you send the mandatory one guinea to Super Mike who's funds must be getting a bit low now, as we don't see so much of him these days and he has been kind to me "the ole spanner man" of late.

Preparation as always is important but not the key with respect to rust and corrosion
Corrosion is not a virus it can not spread like a virus,:)
It is the simple result of a chemical reaction. and contrary to popular belief its not contagious either, although to be brutally honest there some vehicle I wont park next too just in case;)
Some one said it's in the metal, well that,s almost right some of the chemicals are that,s for sure, there are metals more prone to rust than others you can realistically call those cheap metals because the more rust resistance the dearer they cost right up to high grade stainless
So what is the key to halting rust ? its very simple really, just like a fire there are 3 elements required to make it go wild
In a fire its a combustible material, a heat source and oxygen, remove any one of those and a fire is unlikely remove any two and its virtually impossible to make a fire
In rust you need Steel, damp and oxygen and yet again remove any one and rust is rare remove any two and it cant happen
So lets go for the easy method first,
1. get rid of the steel = No vehicle = no rust that's called the 100% method
Next easiest are 2 and 3 together,"The Key"
Treat what rust you have with a rust converter such as jenolite, a long standing proven (acid) based product and then prime, as I said earlier preparation as you have read is not as important as depriving the rust of what it craves. (read on)
then as bill has aid using quality restoration fillers, aluminium based for example but most importantly water proof resins and such fillers are best, the easy sand stuff is easy for a reason it's simply extremely porous 95%+ chalk powder bulk cheap fast trade bodge it and run filler
Please note once filled and sanded it should be painted asap and Primer is NOT water proof but will keep 1 of the ingredients away (oxygen)and that's were many attempts fail, as its left and lets in microscopic damp and the other magic ingredient oxygen, and as we all now know that along with the steel, that all adds up once again to rust and a failed repair
So you really do need good dry days preferably in doors too to starve the cocktail of it's two main ingrediant until the sealed finish coat is applied just like it appears the Bongo was done (y)
and that means both sides of the corroded area , if any part of it can not be sealed even resorting to drilling and waxoil if that is the only way, but if even that is not possible as is the case sometimes, then be prepared to just slow it down and not cure it.
Cutting out and welding in new steel is not a cure either unless as already stated 100% of the new metal and weld can be seal both sides, this is just another slow down exercise
I sincerely hope you now have an honest understanding of rust and corrosion and the difficulty in curing it even for the "Experts out there.
My favorite saying was "Well if they couldn't get it right at the factory what chance do i have now its assembled":doh:

Geo
 
OP
OP
MattR

MattR

LIFE MEMBER
Aug 18, 2013
4,083
37,358
Beds
Funster No
27,578
MH
Panel van
Exp
Years
Mercs from 1999 to 2003 are very prone to rust,,,,cheap steel,,,BUSBY.

Ours is 1996/7 - I hope that it is better metal than the later ones - it seems to be lasting longer than many that I have seen from the early 2000s but I want ours to last for much longer so am hitting every rust spot I can find ASAP.
 
OP
OP
MattR

MattR

LIFE MEMBER
Aug 18, 2013
4,083
37,358
Beds
Funster No
27,578
MH
Panel van
Exp
Years
I have only ever had old vehicles so know where your coming from I cut back and patch then clean till bright with grinding
disk this gives a rugh finis
treet with a zinc based primer then finish with good quality filler not the essay sand crap
I usually mix in a bit of liquid resin this helps to get a good bond with the repair then use a high build primer then top coat
I then treat any areas with a mix of under seal and wax oil
Bill

@Willdbill - what do you mix the liquid resin with, what primer to do you use and what filler do you use?

Rust a comprehensive lesson
As a guy who cut his teeth on welding and vehicle restoration Ill give you free of charge the benefit of my many years experience, provided you send the mandatory one guinea to Super Mike who's funds must be getting a bit low now, as we don't see so much of him these days and he has been kind to me "the ole spanner man" of late.

Preparation as always is important but not the key with respect to rust and corrosion
Corrosion is not a virus it can not spread like a virus,:)
It is the simple result of a chemical reaction. and contrary to popular belief its not contagious either, although to be brutally honest there some vehicle I wont park next too just in case;)
Some one said it's in the metal, well that,s almost right some of the chemicals are that,s for sure, there are metals more prone to rust than others you can realistically call those cheap metals because the more rust resistance the dearer they cost right up to high grade stainless
So what is the key to halting rust ? its very simple really, just like a fire there are 3 elements required to make it go wild
In a fire its a combustible material, a heat source and oxygen, remove any one of those and a fire is unlikely remove any two and its virtually impossible to make a fire
In rust you need Steel, damp and oxygen and yet again remove any one and rust is rare remove any two and it cant happen
So lets go for the easy method first,
1. get rid of the steel = No vehicle = no rust that's called the 100% method
Next easiest are 2 and 3 together,"The Key"
Treat what rust you have with a rust converter such as jenolite, a long standing proven (acid) based product and then prime, as I said earlier preparation as you have read is not as important as depriving the rust of what it craves. (read on)

then as bill has aid using quality restoration fillers, aluminium based for example but most importantly water proof resins and such fillers are best, the easy sand stuff is easy for a reason it's simply extremely porous 95%+ chalk powder bulk cheap fast trade bodge it and run filler
Please note once filled and sanded it should be painted asap and Primer is NOT water proof but will keep 1 of the ingredients away (oxygen)and that's were many attempts fail, as its left and lets in microscopic damp and the other magic ingredient oxygen, and as we all now know that along with the steel, that all adds up once again to rust and a failed repair
So you really do need good dry days preferably in doors too to starve the cocktail of it's two main ingrediant until the sealed finish coat is applied just like it appears the Bongo was done (y)
and that means both sides of the corroded area , if any part of it can not be sealed even resorting to drilling and waxoil if that is the only way, but if even that is not possible as is the case sometimes, then be prepared to just slow it down and not cure it.
Cutting out and welding in new steel is not a cure either unless as already stated 100% of the new metal and weld can be seal both sides, this is just another slow down exercise
I sincerely hope you now have an honest understanding of rust and corrosion and the difficulty in curing it even for the "Experts out there.
My favorite saying was "Well if they couldn't get it right at the factory what chance do i have now its assembled":doh:


Geo

Many thanks for this info @Geo . I am trying to deprive the metal of humidity / water but some areas of rust are impossible to get behind, as you have mentioned so surface treatment will have to surfice until the rust comes through again and I can confirm that the rust was not initiated by stone chips etc.

What aluminium filler do you recommend? I was about to use Isopon 38 but I've read some reviews suggesting that Upol Easy sand is better. However, both are are regarded as easy sand. I don't mind working a bit harder if a different filler is more effective but not so easy to sand. Do you think that Davids ISOPON Metalik Paste would be OK? http://www.halfords.com/motoring/pa...preparation/davids-isopon-metalik-paste-250ml or this

Subscribers  do not see these advertisements

 
Nov 18, 2011
11,856
42,474
Planet Earth
Funster No
18,938
MH
A van
Exp
Over 25 year's
@Willdbill - what do you mix the liquid resin with, what primer to do you use and what filler do you use?
I just mix a small amount with standard body filer It works fine with any
I use just a zinc based primer you get from any motor factors I think Halford is a rip off
Bill



Many thanks for this info @Geo . I am trying to deprive the metal of humidity / water but some areas of rust are impossible to get behind, as you have mentioned so surface treatment will have to surfice until the rust comes through again and I can confirm that the rust was not initiated by stone chips etc.

What aluminium filler do you recommend? I was about to use Isopon 38 but I've read some reviews suggesting that Upol Easy sand is better. However, both are are regarded as easy sand. I don't mind working a bit harder if a different filler is more effective but not so easy to sand. Do you think that Davids ISOPON Metalik Paste would be OK? http://www.halfords.com/motoring/pa...preparation/davids-isopon-metalik-paste-250ml or this
 
OP
OP
MattR

MattR

LIFE MEMBER
Aug 18, 2013
4,083
37,358
Beds
Funster No
27,578
MH
Panel van
Exp
Years

Thanks @Willdbill . I used to think that Halfords was a complete rip-off too but I went there with a voucher that I had been given from colleagues and found a number of things that I needed. When I compared the prices to online suppliers, everything that I wanted was cheaper in Halford's store than off Amazon or other online stores.

Subscribers  do not see these advertisements

 
Last edited:
OP
OP
MattR

MattR

LIFE MEMBER
Aug 18, 2013
4,083
37,358
Beds
Funster No
27,578
MH
Panel van
Exp
Years
Me again.

I'm back to treating rust, having done some work last summer. My new areas to be treated have been prepared and treated with Jenolite stage 1 but my stage 2 is too thick now - I guess that some of the solvent evaporated when I was using it last year. Can I thin it and if so, what would be the best thinner to use for it?
 
Nov 18, 2011
11,856
42,474
Planet Earth
Funster No
18,938
MH
A van
Exp
Over 25 year's
Me again.

I'm back to treating rust, having done some work last summer. My new areas to be treated have been prepared and treated with Jenolite stage 1 but my stage 2 is too thick now - I guess that some of the solvent evaporated when I was using it last year. Can I thin it and if so, what would be the best thinner to use for it?
Go buy new don't compromise for the sake of a few pounds
That's the tigh bodger talking that's bogging my exhaust :rofl:
Bill
 
OP
OP
MattR

MattR

LIFE MEMBER
Aug 18, 2013
4,083
37,358
Beds
Funster No
27,578
MH
Panel van
Exp
Years
Go buy new don't compromise for the sake of a few pounds
That's the tigh bodger talking that's bogging my exhaust :rofl:
Bill

I was hoping to finish it today. I used cellulose thinners but they evaporated so quickly that I didn't have much working time. I wonder what solvent was used originally.

Subscribers  do not see these advertisements

 
Nov 18, 2011
11,856
42,474
Planet Earth
Funster No
18,938
MH
A van
Exp
Over 25 year's
I was hoping to finish it today. I used cellulose thinners but they evaporated so quickly that I didn't have much working time. I wonder what solvent was used originally.
I think it's water based when I worked on the rigs we used a product similar to it and used to dilute with fresh water
Try a small amount on a bit of rusty exhaust and see what happens
Dilute with water egg cup full diluted back with water see what happens
Bill
 

DuxDeluxe

LIFE MEMBER
Jul 10, 2008
14,627
72,223
Planet Zog
Funster No
3,243
MH
A woosh bang van
Exp
since 2008
I think it's in the steel or the quality of the steel. We woul associate materials used in quality brands as being of a high quality but it's not always the case. If the actual steel is not great it will fail and especially in the more exposed or prone areas. I'm no metallurgist but that's maybe what it is .
Mercedes of that vintage are very prone to rust in all the wheel arches, tailgate/boot and also the front suspension mountings. For the rust2rome Merc (E430 2001) we had to source a new tailgate and both front wings on fleabay plus there was some creative welding required where the spare wheel was stored. 175k miles and counting, though....
 
OP
OP
MattR

MattR

LIFE MEMBER
Aug 18, 2013
4,083
37,358
Beds
Funster No
27,578
MH
Panel van
Exp
Years
Mercedes of that vintage are very prone to rust in all the wheel arches, tailgate/boot and also the front suspension mountings. For the rust2rome Merc (E430 2001) we had to source a new tailgate and both front wings on fleabay plus there was some creative welding required where the spare wheel was stored. 175k miles and counting, though....

It seems that our wheel arches are a little prone at the front but not at the rear. The issue we have is where vents have been fitted to the side panels - there is rust appearing that the base of each vent where the screws have penetrated the steel panels. I have a couple of rust spots where the paint appears to be thin. A few small bits to deal with - hoping that it will last for 100,000s or miles more.

Subscribers  do not see these advertisements

 

DuxDeluxe

LIFE MEMBER
Jul 10, 2008
14,627
72,223
Planet Zog
Funster No
3,243
MH
A woosh bang van
Exp
since 2008
It seems that our wheel arches are a little prone at the front but not at the rear. The issue we have is where vents have been fitted to the side panels - there is rust appearing that the base of each vent where the screws have penetrated the steel panels. I have a couple of rust spots where the paint appears to be thin. A few small bits to deal with - hoping that it will last for 100,000s or miles more.
It was the cheap Russian/Chinese steel and the cutback on quality made what was bulletproof into something rather rotting. W209's especially.
 
OP
OP
MattR

MattR

LIFE MEMBER
Aug 18, 2013
4,083
37,358
Beds
Funster No
27,578
MH
Panel van
Exp
Years
It was the cheap Russian/Chinese steel and the cutback on quality made what was bulletproof into something rather rotting. W209's especially.

I hope that our vehicle was made a little earlier than the cheap steel of that Mercedes started to use. Ours looks like it is rusting in the most likely area and where screws have been added to the panels.
 
Aug 19, 2013
2,915
4,214
Wells, Somerset
Funster No
27,611
MH
Elddis 115
Exp
since 2004
Mercs from 1999 to 2003 are very prone to rust,,,,cheap steel,,,BUSBY.
It's just that they were not galvanised until 2004 or thereabouts. And the earlier square (90s, 504d's?) ones were even worse. So much for German build quality.
With Bongos, the worst thing was the double pleated skin on the rear wheel arches. Get a competent specialist to cut and rebuild. Not easy, but should give a few more years.

Subscribers  do not see these advertisements

 

Join us or log in to post a reply.

To join in you must be a member of MotorhomeFun

Join MotorhomeFun

Join us, it quick and easy!

Log in

Already a member? Log in here.

Latest journal entries

Funsters who are viewing this thread

Back
Top