Underbody/Floor

[RossR]

Hi All,

I have a 1958 Minor 1000 (it was my first car about 30 years ago) and
having sat in my garage for the last 20 years have finally got round to starting the restoration.

I'm just about to finish scraping/cleaning the underseal from both under the car and the floor on the inside. I have read a lot of conflicting advice on what to put back on in place of the underseal and decided to go the zinc primer/ chassis black route.

I am just looking for some confirmation that there are no major problems with my plan which is:

1. Finish cleaning the underseal and wire brush to bare metal.
2. Carry out any welding.
3. Wash with milkstone remover to treat any small areas of surface rust.
4. Prime with zinc rich priimer (brush on)
5. Seam seal.
6. Stone chip.
7. Finish with Chassis Back.

Any comments/advice woouth be most welcome

Thanks

[MarkyB]

8.Squirt some Waxoyl into box section etc

[PeteC]

You're doing pretty much the same as me by the sounds of it. I'd recommend you take a look at using the Bilt Hamber Electrox paint for the big areas. Here's an overview for you:

http://www.bilthamber.com/electrox.html

Also, you might want to take a look at this for those awkward corners that inevitably have a bit of light surface rust:

http://www.bilthamber.com/hydrate80.html

They also do a very good de-rusting range of products, well worth checking out.

The other thing I would recommend is to use spray the galvanise paint for the difficult access points, corners and box sections etc. Rustoleum's Hard Hat range is very good stuff, although like any of these paints it has to be applied to bare metal.

One thing to bear in mind - I'm not too sure about how a stone chip paint will adhere to the cold-galvanise surface, so you may want to put on a coat of etch primer which will give some grab.

[morrisman1]

Personally, i would get the underbody sandblasted, mainly around the seams but nowhere that it would cause issues. Then i would use POR15 rust preventative paint straight onto the bare metal, when dry sand the shine off it and paint again, and repeat once more. Spraying the POR15 will get the paint in more places i would think.

POR15 drys rock hard and blocks out oxygen so nothing rusts. It sticks very well so long as your surface isnt shiny smooth and it will be there for ever.

[GeorgeHurst]

I've been impressed by the write ups on POR15 and think I may use it instead of waxoyl when I do the underbody of my car.

The process stated in their literature is to clean the underside, degrease it with 'Marine Clean', treat any rust and bare metal with 'Metal Ready' and then paint over 'POR15 Rust Preventative Paint'. It is UV sensitive, so perhaps one needs to then top coat it with their 'Chassis Black'.

It sounds like an impenetrable barrier, so probably no need to waxoyl on top? Though one would need to Waxoyl in the box sections obvioulsy.

Sorry to potentially hijack this thread with the following comment, but has anyone any bright ideas of how to get good access to the underside without a rollover jig or lift? I'm not sure I would be able to do a very good job with a pressure washer scrabbling under the car with 5" of clearance!

[Dean]

I used POR15.

Firstly I completely cleaned the underside of the car, not necessarily to bare metal, but enough to expose any rust. A nice sharp chisel removed any loose paint and cellulose thinners took care of any grease. You could use Marine clean instead of thinners.

I then sprayed with Metal ready, copious amounts, keeping it wet for 30 mins.

I then got a garden hose and completely blew away the metal ready with fresh clean water.

The underside looked liked it had been frost bitten as the metal ready had etched the material. Waited until completely dried.

I then painted the underside with POR15 with three coats... this took ages and was tedious, but rewarding afterwards. I used the light grey version so I can see if any rust pops out in future.

If using POR15 and the car isn't tilted on it's side.. wear a paper balaclava, marigolds and goggles, this stuff doesn't wash off!!! If you have a job where presentation is everything, globs of paint on your face for weeks doesn't win prizes.

[GeorgeHurst]

Dean, do you know how many 0.5 litre tins of POR15 you used to do the whole underside?

[bmcecosse]

" how to get good access to the underside without a rollover jig or lift? " - Dig a pit - or construct a ramp - like the display ones in car sales forecourts! Or even build two wide brick walls - at the appropriate spacing - and long (well supported) planks to drive the car onto the walls ? Or as most do - either beg/borrow/steal (last resort - BUY) a set of car ramps - or just jack it up and support it securely!

[Dean]

George, I bought 3x946ml tins. This covered:
All the underside.
All the inner wings inside the wheel arches and the bit the other side of the front door pillars.
All inside 4 wings.
Inside of two bumper valences.
Inside of my cheesegrater.
Inside of my sill covers.

So to answer your question, I'm guessing two 948ml's will be ample.
If you can get hold of some empty painting tins, you'll find these will be useful. POR15 comes in a double sealed tin and the lid gets damaged very easily. Rendering the paint to start curing in the tin for when you next need it!!

Their paintable seem sealer is good too... use this to push into any seams underneath incase the paint doesn't quite go in.

[moggyadventurer]

I would tend to agree in sand blasting, just make sure the sand is not contaminated or 5 years down the line problems will occur. Once back to bare metal repair any areas that are required and apply paint processes. I would reccommend dinitrol products for box sections and as a final underseal.

[GeorgeHurst]

Thanks for the suggestions Roy, car ramps and scrabbling underneath will probably be the only course of action.
And thanks Dean for that info, I can only find 0.5 L tins for about £17, where did you get the larger tins from? The only place I can see that sells it is Holden or Frost.

[Dean]

Frost were the people I used George.

[bmcecosse]

If you can buy it from Frost - you can usually get it for much less elsewhere!

[GeorgeHurst]

Thanks Dean

[PeteC]

Sort of hijacking the thread too, I'm fabricating up a frame to spin the traveller at the mo. Should be a lot less back-breaking than digging a pit, and will certainly help improve my welding if I'm not doing it from underneath!