Treating inaccessible areas

[Torqu-E-Cycles]

Thought I best make a different post on this one as not to get confusing? Sorry I'm still quite new here!

I'm removing rust and repairing my old mini and currently on the roof corners, cutting out and replacing with new formed steel, once the sections are in there's no way I can get in behind to paint etc, I have probably a 5mm gap between the skin and a stiffening rail, there's surface rust in other places too I can't access.

Whats your opinion on coatings to seal it, por15 or waxoyl or something different? Also have loads of interior panels that are brown rusty, was thinking of por15 the whole inside everywhere thats covered with carpet etc, the car will probably never see the rain! Can por15 be top coated with 2k?

Thanks again, you are a brilliant bunch I wish I found this place sooner!!

 

[Wildefalcon]

If you can access it, clean with citric acid, mixed with wallpaper paste, not too runny, so it doesn't go into the places it can't be removed from. Neutralise with washing soda.

Paint with 2k non iso zinc phosphate epoxy, after keying with sandpaper.

Then epoxy mastic.

Then whatever you like, 2k. I'd colour match the car. Nearest RAL.

For the inaccessible, a creeping cavity wax. Bilt hambler, dinotrl, lanoguard etc.

Not waxoil, it dries out.

 

[ajlelectronics]

POR-15 is a synthetic and cannot be overcoated, there is nothing that POR-15 can do which epoxy cannot do better. You have epoxy in stock, so that's the stuff to use.

 

[Dcal]

For the inside I'd use an epoxy mastic, something like Jotamastic 90A. The A means it has added aluminium which will provide galvanic protection as well.
It doesn't need perfect prep but the better the prep the longer it will last.
As this is on the inside it shouldn't take much abuse so give it a clean then a quick rub with 120 grit paper and it will last for many many years.

For the bits you can't reach use a good wax, I've started using ACF50 as it's well recommended on here and it is nice to use.

 

[steveo3002]

make sure you really really want por15 , it works well when it works , but get it slightly wrong and it peels off in sheets , id not use it again

epoxy does everything it claims to do or better , and the cans keep once open unlike por15

 

[graffian]

make sure you really really want por15 , it works well when it works , but get it slightly wrong and it peels off in sheets , id not use it again

epoxy does everything it claims to do or better , and the cans keep once open unlike por15

I ignored the throw the can away on the back of the por15 can, the paint didn't go off.
I put holes in closed section and mist inside with waxoyl or dinitrol, I use it hot from a
pressure pot and theres not need to thin it.

ACF50 seems no better than way oil in keeping rust at bay.

 

[Torqu-E-Cycles]

Thanks for all the replies, I'll use epoxy

 

[steveo3002]

ACF50 seems no better than way oil in keeping rust at bay.

if its used where it wont wash off its pretty good , after all oil remains wet , flexible , soaks into gaps , self repairs etc...

 

[MG David]

When it comes to removing rust from the inside around the edge, you could turn the shell upside down and have a citric acid lake in the roof. tip it a little one way to get at that edge of the roof and then tip it a bit an other to get to an other edge of the roof.

Then neutralise and coat as others have discussed.

 

[Dcal]

I'm probably one of the worst offenders for doing far more than necessary (I'd probably grit blast the whole shell) but if you follow the recommendation on the TDS for say, Jotamastic 90A, there is no need to get rid of every last speck of rust.
It is designed and certified so it can be applied over well adhered rust and if the rust is rubbed down any remennts will certainly be well adheared and ready for the epoxy.

I assume the shell is dry as it is.
Once you start adding acid, alkali, water etc. they could make their way into the seams with the potential to cause issues further down the line.

My recommendation would be, if you can keep it dry, get it painted and then get wax into any open seams and closed sections.

There comes a point when good enough is good enough and any more is just wasted effort with the potential for the job to become overwhelming.

Of course it's your project so it your decision and you can do as much or as little as you want.

 

[Smallfry]

Further to previous comments based on 40 odd years of experience........

Waxoyl is complete and utter rubbish. I am trying out Lanoshield at the moment and liking it so far (except the price) Jury is still out on applying it every year though. Is pleasant to use compared to oil based products, However, it is impossible to spray with hand operated sprayers, despite what "they" say.

Of the oil based products, I would say Bilt Hamber is better than Dinitrol, but thats just my opinion.

POR15 is OK if applied to immaculate metal under laboratory conditions. Tried it once, never again.

There is a single pack product called Deproma Rustproof that I used to use. Absolutely brilliant. You really could paint it onto greasy and damp metal, and it would stay there. It comes from France though, and there are no UK agents any more.

Never actually tried any epoxy type paints personally, so cannot comment.

 

[ajlelectronics]

Never actually tried any epoxy type paints personally, so cannot comment.

Give it a try, you will become a convert!

 

[Burdekin]

You can now get can of 2k epoxy aersols. Bilt hamber see injection wands for aerosols so you can poke it through the gap and give the welded areas a good couple of coats. Works a treat. Or drill a access hole if needed.

Por15 is fiddly expensive rubbish with fantastic marketing and in my experience delaminates after a little while. Stick with the epoxy primers as recommended above.

Bilt Hamber S-50 is the dogs when it comes to anti-corrosion wax oils. It is also based on lanolin and it's ability to creep into seams is amazing.

 

[Burdekin]

Further to previous comments based on 40 odd years of experience........

Waxoyl is complete and utter rubbish. I am trying out Lanoshield at the moment and liking it so far (except the price) Jury is still out on applying it every year though. Is pleasant to use compared to oil based products, However, it is impossible to spray with hand operated sprayers, despite what "they" say.

Of the oil based products, I would say Bilt Hamber is better than Dinitrol, but thats just my opinion.

POR15 is OK if applied to immaculate metal under laboratory conditions. Tried it once, never again.

There is a single pack product called Deproma Rustproof that I used to use. Absolutely brilliant. You really could paint it onto greasy and damp metal, and it would stay there. It comes from France though, and there are no UK agents any more.

Never actually tried any epoxy type paints personally, so cannot comment.

Bilt Hamber S-50 is Lanolin based also.

 

[Smallfry]

Bilt Hamber S-50 is Lanolin based also.

Are you sure about that ? It doesnt smell or feel like it to me. I always seem to get more product on myself rather than the vehicle.

 

[bert]

If you have rust in the seams on the roof it will be all the way round not in the local areas you have cut out.

Ideally fit a new roof skin so you can clean up the can't rails properly

 

[Jack_K]

If you have rust in the seams on the roof it will be all the way round not in the local areas you have cut out.

Ideally fit a new roof skin so you can clean up the can't rails properly

I have the same problem, if not replacing the roof (it is a van) what would you do. Obviously it won't be the best but it will have to do.

 

[MG David]

You could drill out all the spot welds holding the roof on. Derust the flange on the roof and the flange on the body by sand blasting of sanding disk on an angle grinder etc. Then practise until you are a good at brazing with a gas torch. Once you are happy with your skill level, braze the roof back on taking care to get the film of brazing metal in the full depth of the flange seam.

Alternatively do the same but with panel adhesive rather than braze.

 

[bert]

The roof skins are continuous welded so no chance of getting it off without destroying it.

Sadly van roofs are not available so it's a matter of replacing what you can

 

[bricol]

I have to say, I keep shoving waxoyl, bought 25 yrs ago, into an old Pug 106 that lives outside, as it was cheap, and it was a cheap car . . . still not had to do any underside repair work - now 32 yrs old.

Lancia was dinotroled 15 yrs ago - 5 yrs ago, after repairs, it was noxudol-ed and so far seems okay.