Advice needed - paint, rustproofing, rustoleum, oldunderseal

[aogrady]

Hi!

Really need to get the body cavity waxed, and tidy up the underneath as it's starting to get tatty. Looking for suggestions as how to get rid of the underseal, some of it flakes off with a finger nail. Can the loose stuff be flaked on, and then painted over with rustoleum? I want to use this as i can get it colour matched, but will it be ok on the non rusty bits, or does it need rust to stick too? Surely it will just act like normal paint and seal hard over the old underseal and paint?

I guess, any kind of paint is gonna be better than leaving the rusty bits, but would appreciate some advice please?

Pics of the underneath:

I have ankor waxed the rusty bits on the front floor to stop then getting any worse, again rustoleum should be good here, but will need some degreaser or something to get rid of the wax, any ideas?

Cheers!

Alistair

 

[mattp]

Alistair,

I used a blunt scraper to remove as much of the old underseal as I could and petrol on the rest. I'm not suggesting using petrol as it is a little dangerous (using petrol is what some old boys told me years ago and did mention the dangerous but good bit) however in retrospect I would have probably used petrol on all of it and a big paint brush -a good supply of toothbrushes is a must. I will be shotblasting any areas that have rust from stone chips and will then be priming, stoneshipping and possibly paint.

The problem with doing any of this take time and I mean lots and lots of time. What it might be easier to do it look at the areas that have gone rusty and treat these and paint them locally with waxoil applied everywhere else. I would then suggest that if you are to keep the bus that you work on little sections over the bus with time and clean off the waxoil/underseal/treat and rust/paint as you go. May take a year or two but worth it -I've been doing this for the last 2 years and almost there


The thing about scrapers is that they take little nicks out of the paint and the reason I'd have used petrol is that on the arch pictured below I would of just has loads of nice original paint.

 

[dubdubz]

is the dangerous bit about petrol - just cos it's a flammable liquid and the usual 'petrol' reasons??

or does it stain/damage the underlying paint if not careful?

would std cellulose thinners work out cheaper? and do the same thing?

 

[Bookwus]

Hiya ao,

I do agree with matt about the time involved. Lots of it! And all of it on your back with dirt, crud, and rust falling in your face. Not especially fun, but it is time well spent.

Were it me, I would go about this job thusly..........

1. Remove aforementioned dirt, crud, and rust by mechanical means. Scraping, brushing, drill attachments, etc. The idea here is to get down to a clean painted surface. You will however, go beyond that to bare metal in places.

2. Treat any bare surfaces with a rust converter. I've used all sorts of these converters. Basically, they take the "life" out of iron oxide by converting it to an inert material. In my mind, you must do this step (and do it very well) or the problems you are now seeing will simply reappear later.

3. Paint any bare metal spots (ie, paint over the rust converter used in step #2) in order to seal them up.

4. Undercoat. A lot of folks over here in the States use a rubberized undercoating available in spray cans. Works reasonably well. I use it in wheel wells where a little "cushion" againts the spray of road debris is desireable. In the structural underbody WaxOyl seems to be a much better choice to me. This stuff will actually penetrate and seep into very small spaces when it's applied. That's a very good thing!

 

[Pike]

If you use Rustoleum don't apply it too thick as it sort of skins over and then takes forever to dry properly especially over seam sealant etc. It does not need rusty metal for it to stick properly, just key the old paint with something like scotchbrite, degrease then paint (I painted my Beetle bodywork with it )

 

[aogrady]

Hi!

Ok, looks like scraping off as much of the old crap first, degreasing, and then rustoleum - a little bit at a time, as said, gonna take some time. And i think a few thin coats?
Good to know that rustoleum will stick to normal paint (keyed) not just rust, as not all of the underneath is rusty.

OK then, what whirly type wheel can i use on a drill to speed things up without going too crazy and going down to metal?

Thanks for the advice all!

Cheers!

Alistair

 

[angus]

When I took my underseal off, I found gentle warming with a blow torch (not too fierce though...) softened it enough to then easily scrape off with a paint scraper - careful of nicks though - maybe use a plastic version (one of the thicker filler spatulas should work) Then cleaned off the residue with brake cleaning fluid (or petrol - usual warnings apply - dodgy for skin etc)
You can see all my pics in the 'show' forum. Van rolled on side made a massive difference...

 

[aogrady]

When I took my underseal off, I found gentle warming with a blow torch (not too fierce though...) softened it enough to then easily scrape off with a paint scraper - careful of nicks though - maybe use a plastic version (one of the thicker filler spatulas should work) Then cleaned off the residue with brake cleaning fluid (or petrol - usual warnings apply - dodgy for skin etc)
You can see all my pics in the 'show' forum. Van rolled on side made a massive difference...

Hi!

Good point about heat, and reckon i could shift a fair bit with just a plastic scraper

cheers!

Alistair