Which type/brand of undercoat to use and preperation tips.

[mikey]

Hi all,

After some help regarding undercoat paint to use during a prolonged restoration.

I have my shell sitting up on a rotisserie and I will be sandblasting myself in the shed.

Have researched POR 15 products and will be using this to paint the floor pans on the inside and underneath as well as the firewall.

As this shell was purchased as an unfinished project there are areas that have been sanded down to bare metal and left uncovered and have surface rust on them. Areas like the B pillars inside, the rim of the roof inside where the headlining attatches.

What I would like to know is what sort of undercoat (and prep tips) should I use when I sand areas back to bare metal. Of course this is a long way from completion and will sand back as I go so the undercoat will be a protective measure. In other words not final coating for ages.

Thanks   M

[Jonno]

mikey,

If you don't want to do anything fancy you can just cover the bare metal in lanolin (get a Lanotec hand spray from the hardware store or supermarket). I stripped my ute to baremetal and it sat in the garage for about a year (through a melbourne winter.....back when it rained in melbourne!) covered in this way, waiting for a panel beater. There was no rusting at all and, when it finally came to epoxy primer, no obvious ill effects from sitting so long.  The guys who recommended this approach (Performance Coachworks in Berwick) just work in bare metal...they don't do paint....so I figured they knew what they were talking about.

Jon

[FC427]

Mikey  I use a clear sealer that I get from the sand blaster it can be brushed or sprayed and is easy to remove later.It is very thin and goes a long way cost about $20 a liter which is more than enough to do a whole car . I have had cars in this sealer for a few years with no rust problems........FC427.........

[mikey]

Hi guys thanks for the replies,
                                         Jonno the lanoline sure sounds like it would do the trick but I get the impression that it would never dry and always be wet/greasy. This would be a hassle as work on the shell body is ongoing and don't want grinding dust, paint dust and rubbish sticking to it. Feel free to correct me if I am wrong.

427 regarding the clear coat you say the coating is easy to remove, I cant see that being a problem on flat areas but would see it being a bit tricky to remove from around the rim of the roof where the sharp toothed strip is. I think it's for the headlining and strip to sit in. In this instance I feel undercoat would be better but I suppose the nuts of my original question is what type on undercoat to use.

I suppose I need to know if there is acrylic type undercoat that can only be used with acrylic paint etc etc in other words do you have to use specific undercoat for specific type paint or is there a compatible undercoat for all paint types?
I have not worked out what paint is to be used on the car yet but don't want to sand a heap of surface rust and old paint off and undercoat with the wrong type and have to remove it later.

Not really a problem with that except it would be hard to get it out of all the areas again in places like gutters and door pillars.

Cheers   M

[FC427]

Mikey to remove the sealer just wash it in general purpose thinners "Presto" it's gone The guy at the blaster says it is OK to paint over but I always wash it off.  I find it the best and easiest method and its clear .  .........FC427........

[mikey]

Ok 427, I had incorrectly assumed that it had to be sanded off, cheers for that info. will try and find some.

As a head start to locating some do you or anyone know if it available at auto paint stores, I suppose I could actually ring them

Thanks once again    M

[FC427]

Mikey Try your local sandblaster I have never been able to get it else where. .....FC427......

[NO NAME]

alternatively you could just strip a area, as large as possible and spray it in epoxy, unlike etch primer epoxy seals and can have normal plastic body filler applied on top, you can grind of the areas to be replaed, weld in the patch and just scuff the near epoxy then apply more epoxy to the new patch, if you watch those foxtel shows were they build cars in USA they all do it this way.
 I use a cheap one by debeer from autolac but there are a few cheap ones starting to come onto the market now that the local paint companies like concept are starting to do epoxy aswell, epoxy is used by mercedes benz and bmw but it also has big advantages in a long term build, you can just leave it in epoxy for a couple of years then work on it bit by bit.
 you can use epoxy under acrylic, 2k primer is better to use under the acrylic but you should have proper protection gear becuase the iso in the hardener MIGHT kill you if you get in on your skin.

[NO NAME]

i used por 15 and got the shits with it, you will need to use the por 15 cleaners and tie coat too, i found if everything wasnt perfect it could peel so i striped it of, i found crappy old killrust enamel seems to get in and stick well to inside bits like sills and pillars but remember nothing will go over it so dont use it under acrylic or 2k.
 also, rust will start to form in about 40 minutes after blasting, if it gets left overnight, treat the metal with a deoxidiser before primer,