removing rust from rear arch
Discussion
I posted this in GG but wasn't met with a resounding response.
I think there are a couple of posters, from memory, who have sorted rust on their 5 in the past, so i'm hopeful to get some good tips.
I'm not a total DIY idiot so i'm hoping with time and prep this job wont be too much of a big deal, even though I havn't really done anything like this before.
I have purchased from Halfrauds the following:
Various et & dry sheets
Hammerlite Antirust primer
Waxoyl underseal (to give the underside and seals a good coating)
Clear Lacquer
BRG Spray paint
Isopon p38 Filler
Filler applicator
I intend to sand the bubbling area and its surroundings back to bare metal, making sure to expose clean metal in the process, and feather the edges as best as poss, removing ALL rust.
Use a fine coating of filler to smooth over imperfections. Rub down until totally smooth to the touch. Then add a few coats of primer, as heavily as possible without causing runs. Then allow to dry for a few days. Rub down again to key the surface and add topcoat. Then lacquer if necessary once the colour coats are dry. If the colour surface is not immaculate use the Farecla paste compound to smooth and polish it.
I'm going to give myself 3 days to do this in.
Any tips?
I think there are a couple of posters, from memory, who have sorted rust on their 5 in the past, so i'm hopeful to get some good tips.
I'm not a total DIY idiot so i'm hoping with time and prep this job wont be too much of a big deal, even though I havn't really done anything like this before.
I have purchased from Halfrauds the following:
Various et & dry sheets
Hammerlite Antirust primer
Waxoyl underseal (to give the underside and seals a good coating)
Clear Lacquer
BRG Spray paint
Isopon p38 Filler
Filler applicator
I intend to sand the bubbling area and its surroundings back to bare metal, making sure to expose clean metal in the process, and feather the edges as best as poss, removing ALL rust.
Use a fine coating of filler to smooth over imperfections. Rub down until totally smooth to the touch. Then add a few coats of primer, as heavily as possible without causing runs. Then allow to dry for a few days. Rub down again to key the surface and add topcoat. Then lacquer if necessary once the colour coats are dry. If the colour surface is not immaculate use the Farecla paste compound to smooth and polish it.
I'm going to give myself 3 days to do this in.
Any tips?
Without meaning to sound rude, why are you doing it?
IMO using filler is a sub standard repair, and especially as you're new to the repairing game it's likely the rust will just reappear after a year or two.
I noticed a tiny bubble under the paint on my front offside wing when I was washing my '5 at the weekend, but rather than repair that spot in isolation I'm putting a new wing on to ensure it never comes back.
I realise your rust is at the back so a new panel would be prohibitively expensive (front wing is only £80) but why not have a 'proper' (i.e. cutting, welding, painting) job done by a good local bodyshop?
Again, sorry if the above appears rude - it isn't intended that way. I'm just a perfectionist so won't tackle a job unless I know the outcome will be as good as or better than new i.e. you're much braver than I when it comes to repairs!!
IMO using filler is a sub standard repair, and especially as you're new to the repairing game it's likely the rust will just reappear after a year or two.
I noticed a tiny bubble under the paint on my front offside wing when I was washing my '5 at the weekend, but rather than repair that spot in isolation I'm putting a new wing on to ensure it never comes back.
I realise your rust is at the back so a new panel would be prohibitively expensive (front wing is only £80) but why not have a 'proper' (i.e. cutting, welding, painting) job done by a good local bodyshop?
Again, sorry if the above appears rude - it isn't intended that way. I'm just a perfectionist so won't tackle a job unless I know the outcome will be as good as or better than new i.e. you're much braver than I when it comes to repairs!!
Wigeon Incognito said:
Without meaning to sound rude, why are you doing it?
IMO using filler is a sub standard repair, and especially as you're new to the repairing game it's likely the rust will just reappear after a year or two.
I noticed a tiny bubble under the paint on my front offside wing when I was washing my '5 at the weekend, but rather than repair that spot in isolation I'm putting a new wing on to ensure it never comes back.
I realise your rust is at the back so a new panel would be prohibitively expensive (front wing is only £80) but why not have a 'proper' (i.e. cutting, welding, painting) job done by a good local bodyshop?
Again, sorry if the above appears rude - it isn't intended that way. I'm just a perfectionist so won't tackle a job unless I know the outcome will be as good as or better than new i.e. you're much braver than I when it comes to repairs!!
No, doesn't sound rude at all - its a fair question.IMO using filler is a sub standard repair, and especially as you're new to the repairing game it's likely the rust will just reappear after a year or two.
I noticed a tiny bubble under the paint on my front offside wing when I was washing my '5 at the weekend, but rather than repair that spot in isolation I'm putting a new wing on to ensure it never comes back.
I realise your rust is at the back so a new panel would be prohibitively expensive (front wing is only £80) but why not have a 'proper' (i.e. cutting, welding, painting) job done by a good local bodyshop?
Again, sorry if the above appears rude - it isn't intended that way. I'm just a perfectionist so won't tackle a job unless I know the outcome will be as good as or better than new i.e. you're much braver than I when it comes to repairs!!
My main concern is that it will eat into the wing, which will be very expensive.
I have purchased all the bits and bobs for £25. I think it would be more prudent to work with what ive got than get it chopped off and a new one welded on.
I have also heard that the rust proofing on the wings available as an aftermarket product isnt exactly brilliant...
So one year or 2 @ £25 for repairing and my time over the easter weekend.
Or
£150 to get new arch painted primed and welded, with the chance this will rust up in the short term too.
Christ knows how much a new wing will cost you to have fitted properly and painted - I would think it would be uneconomical from my point of view...
princeperch said:
I have purchased all the bits and bobs for £25. I think it would be more prudent to work with what ive got than get it chopped off and a new one welded on.
I have also heard that the rust proofing on the wings available as an aftermarket product isnt exactly brilliant...
So one year or 2 @ £25 for repairing and my time over the easter weekend.
Or
£150 to get new arch painted primed and welded, with the chance this will rust up in the short term too.
Christ knows how much a new wing will cost you to have fitted properly and painted - I would think it would be uneconomical from my point of view...
If it's only £150 to do a proper repair, do it PDQ and don't f_ around with 'repairing' rust. I'm talking from considerable experince here and frankly, it's not worth your time. If there's any rust that has penetrated deep into the panel, it'll be a question of months before it returns no matter how hard you try - if it's in a wheelarch where you can't reach the back side of the panels properly and where inner and outer wheelwells meet, it'll be a question of weeks or days. I have also heard that the rust proofing on the wings available as an aftermarket product isnt exactly brilliant...
So one year or 2 @ £25 for repairing and my time over the easter weekend.
Or
£150 to get new arch painted primed and welded, with the chance this will rust up in the short term too.
Christ knows how much a new wing will cost you to have fitted properly and painted - I would think it would be uneconomical from my point of view...
To rustproof new sheetmetal with no rust for years and years to come OTOH is quite easy.
Edited by 900T-R on Wednesday 12th March 10:37
General advice only, but get yourself some Kurust to chemically stabilise the metal once you've cleaned off most of the rust. Wire wool and a wire wheel are better at getting into the pits than a wet or dry type of sandpaper.
Your primer should be a zinc based one (the zinc grabs the oxygen if the top coat breaks down and stops the chemical reaction IIRC) and the surface should be meticulously clean before you apply the primer. Don't worry about the black residue that's left behind from stabilising the rust, you can paint directly onto that.
Sure, this isn't a perfect repair, but it can buy you time before you start cutting out rusted panels.
Your primer should be a zinc based one (the zinc grabs the oxygen if the top coat breaks down and stops the chemical reaction IIRC) and the surface should be meticulously clean before you apply the primer. Don't worry about the black residue that's left behind from stabilising the rust, you can paint directly onto that.
Sure, this isn't a perfect repair, but it can buy you time before you start cutting out rusted panels.
princeperch said:
tbh i'll probably have a crack at it, as the initial outlay is negligable...
Lets face it, if I f
k it up, whats the worst that can happen? A new wing? I would have to get one of them anyway!
Ill try and remember to take some before and afters...
Fair enough. Lets face it, if I f
k it up, whats the worst that can happen? A new wing? I would have to get one of them anyway!Ill try and remember to take some before and afters...
Do it well and it can buy you some time - I've kept a tiny blister on the LHS rear arch of the Saab that kept re-occurring at by for several years before I could afford to have a proper weld-in repair done... but I've been at it at the same d*mn spot for more weekends than I can remember and eventually, the repair turned out to be a good deal more extensive than if I had it done right away - beggars can't be choosers and all, but right now I'd have preferred to do something more constructive with my time.Must say that I hate to do recurring jobs because they don't give any sense of achievement. I'm alwasys procrastinating over household chores (well I'm single so I sort of get away with it...)
HRG said:
General advice only, but get yourself some Kurust to chemically stabilise the metal once you've cleaned off most of the rust. Wire wool and a wire wheel are better at getting into the pits than a wet or dry type of sandpaper.
Your primer should be a zinc based one (the zinc grabs the oxygen if the top coat breaks down and stops the chemical reaction IIRC) and the surface should be meticulously clean before you apply the primer. Don't worry about the black residue that's left behind from stabilising the rust, you can paint directly onto that.
Sure, this isn't a perfect repair, but it can buy you time before you start cutting out rusted panels.
Yip - got a high zinc content primer and some wire wool in the garage.Your primer should be a zinc based one (the zinc grabs the oxygen if the top coat breaks down and stops the chemical reaction IIRC) and the surface should be meticulously clean before you apply the primer. Don't worry about the black residue that's left behind from stabilising the rust, you can paint directly onto that.
Sure, this isn't a perfect repair, but it can buy you time before you start cutting out rusted panels.
Do I clean back the metal to rust free metal, do a few coats with ku rust, then prime? Or Clean, prime, then ku rust the area then paint over..?
Common sense would dictate the former I guess..
princeperch said:
HRG said:
General advice only, but get yourself some Kurust to chemically stabilise the metal once you've cleaned off most of the rust. Wire wool and a wire wheel are better at getting into the pits than a wet or dry type of sandpaper.
Your primer should be a zinc based one (the zinc grabs the oxygen if the top coat breaks down and stops the chemical reaction IIRC) and the surface should be meticulously clean before you apply the primer. Don't worry about the black residue that's left behind from stabilising the rust, you can paint directly onto that.
Sure, this isn't a perfect repair, but it can buy you time before you start cutting out rusted panels.
Yip - got a high zinc content primer and some wire wool in the garage.Your primer should be a zinc based one (the zinc grabs the oxygen if the top coat breaks down and stops the chemical reaction IIRC) and the surface should be meticulously clean before you apply the primer. Don't worry about the black residue that's left behind from stabilising the rust, you can paint directly onto that.
Sure, this isn't a perfect repair, but it can buy you time before you start cutting out rusted panels.
Do I clean back the metal to rust free metal, do a few coats with ku rust, then prime? Or Clean, prime, then ku rust the area then paint over..?
Common sense would dictate the former I guess..
Clean off the bubbling rust as best as you can, but if there are areas with well bonded paint, just flat it back a bit, I'll explain why in a bit. The Kurust is a single coat application and it will stop the chemical reaction that's occurring, therefore it needs to be applied to bare metal. Apply it sparingly and keep it off good paintwork as it will go black or purple!
Once it's had an hour or so to work and has turned black apply a couple of coats of zinc primer and allow to dry well. If the pitting is minor use a fine filler and flat/prime until you are happy with the finish. Then you can apply the top coat. Spray/flat spray till you are happy with the finish and then apply a clear lacquer. The objective is to seal the area so that oxygen can't get in. If there's no oxygen the chemical reaction can't take place so the rust won't come back. The reason it usually reappears is that the affected area isn't resealed.
If you're working inside an arch you can use black Smoothrite which is designed to be painted over rust and you can be exceptionally liberal in it's use
Waxoyl inside the arch and in any gaps.... It's horrible stuff, but it certainly does what it's supposed to.
The above will give you a functional repair that should last if done correctly. Cosmetically perfect it isn't, but it will prevent the problem getting any worse.
I too have such a project on the horizon - a prospect I'm not looking forward to. Once I apply the grinder (or rather, once my father does so), there won't be much of a wheelarch left, so it looks like I must cut the wing off and get a new one.
Bugger.
The downside to owning a sportscar which everyone who hasn't got one insists on telling me is 'bulletproof'
Bugger.
The downside to owning a sportscar which everyone who hasn't got one insists on telling me is 'bulletproof'
I did actually - and it went ok, its not perfect cosmetically, but it was a functional repair and I was quite pleased with it...
To my shame I dont have pictures, but it went ok.
Its funny you mention it actually, was looking at the arch yesterday feeling rather pleased, and bugger me, if theres not a new spot of bubbling further round the wheel arch at the top.
I'm going to leave it a few more weeks (more to my diary than anything else) then I think i'll have to bite the bullet and get the lot professionally ground down primed and painted.
Problem now is the sill on the same side has a patch of solid rust that ive treated. Should be no problems getting through the MOT, but part of me wonders should I get the sill repair thing from MX5 parts complete with arch and get the whole lot replaced - or should I use the arch I have and get a patch weld of the lower sill piece.
For christs sake - I was told these cars were bullet proof!
To my shame I dont have pictures, but it went ok.
Its funny you mention it actually, was looking at the arch yesterday feeling rather pleased, and bugger me, if theres not a new spot of bubbling further round the wheel arch at the top.
I'm going to leave it a few more weeks (more to my diary than anything else) then I think i'll have to bite the bullet and get the lot professionally ground down primed and painted.
Problem now is the sill on the same side has a patch of solid rust that ive treated. Should be no problems getting through the MOT, but part of me wonders should I get the sill repair thing from MX5 parts complete with arch and get the whole lot replaced - or should I use the arch I have and get a patch weld of the lower sill piece.
For christs sake - I was told these cars were bullet proof!
Ahh good work!
Yes bullet proof, much like my Porsche which is 'double galvanised' so 'doesn't rust' but somehow the rust fairies have found their way in anyway and it's costing me just north of £1k at the weekend to put right... (Sorry, just recoiling after looking at my bank statement.)
I would have thought a good bodyshop would be the most cost effective bet for good repairs on the '5 rather than new panels unless they're particularly cheap.
My bodyshop would charge £30 an hour for metalwork, say 6-8 hours work and the same amount for paint at say 4 hours. Plus maybe £80 for parts. So all in I'd guess at about £380-440.
(Those estimates are based on the work as you describe and the plethora of quotes I've been getting recently.)
Yes bullet proof, much like my Porsche which is 'double galvanised' so 'doesn't rust' but somehow the rust fairies have found their way in anyway and it's costing me just north of £1k at the weekend to put right... (Sorry, just recoiling after looking at my bank statement.)
I would have thought a good bodyshop would be the most cost effective bet for good repairs on the '5 rather than new panels unless they're particularly cheap.
My bodyshop would charge £30 an hour for metalwork, say 6-8 hours work and the same amount for paint at say 4 hours. Plus maybe £80 for parts. So all in I'd guess at about £380-440.
(Those estimates are based on the work as you describe and the plethora of quotes I've been getting recently.)
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