The V8 Owners Forum -

Hi, I'm currently stripping back my MG, and in a few weeks I'll be getting a rollover jig so I can start on the underside of the car.

The plan is to strip back to bare metal, fix the few small holes, spray it with some oxide primer then use something like POR-15.

Questions are;

1. Are there cheaper/better alternatives to POR-15?
2. Can it be sprayed on for a smooth look or is it brush-on only?
3. Do I need to do anything else other than primer + rust prevention (POR15 etc) - i.e. do I need to spray another coat of something on top of the POR15?

cheers

Hi
An obvious question here, is it for road use or track only? Personally I would now be very carefull of these one coat wonder rust preventatives as I will now at some stage soon have to completely strip my slingshot chassis of one such product that just peals off. If it is for road use I would use a stone chip as a final coat, and a good etch primer as the base, I now have no faith at all in these rust preventatives.
Best regards
Mike

Same as on the suspension thread for me, Jotun Jotamastic 87, then topcoat of choice. Don't like POR. Jotun is a non-isocyanate marine 2k epoxy, rated "below waterline". Cheaper and less fussy than POR, and lots cheaper than Epoxymastic.
Have also used automotive 2k epoxies and topcoats.

If you want 'nice', 2k colour topcoat. Otherwise chassis black is tough and low cost.

Not keen on waxes, and hate underseal/schutz. With paint you can see damage and fix it. Glops can split and metal rots away quietly behind. My current car had skins of underseal with literally zero metal behind in places..
No glops on current car and no chips or damage.

Well the MG will be for fast road and track, but mainly fast road.

Can someone recommend a good etch primer please? I'm currently using some red oxide metal primer, that ok?

I've just looked at that Jotun stuff, looks ok, what would I need to spray it on a compressor?

Chassis black, like this;

http://www.ebay.co.uk/itm/Manor-Coating ... 2a1633f3ba

Would I need thinners to spray it on? I just don't want to have a brush finish that's all.

There seems to be a lot of options, anyone used Dinitrol? That comes in a spray can (easier!). But is a wax.


http://www.ebay.co.uk/itm/Eastwood-Chas ... 256f2516a9

This one looks ok? Bit pricey tho!

I might settle for the Manor Coatings one tho as that is cheap as chips.


Or I've found this on screwfix, dirt cheap!

http://www.screwfix.com/p/no-nonsense-q ... 50ml/23091

And then a coat of paint on the top.

thanks for the advice as always.

Hi
I am a bit traditional and would go Red oxide, or something like the eastwood etch primer http://www.frost.co.uk/eastwood-grey-se ... 946ml.html .
However anything intended for marine use below the waterline must be worth considering as the stuff must stick and seal very well to work in that environment. Also being non-cyano you will be able to apply it without killing yourself.
Best regards
Mike

Jotamastic can be thinned & sprayed, or rollered or brushed, I've done all of those. It's tough as nails and doesn't mind a fairly thick coat, also goes over rust etc (marine).
I just used 2k thinners though they do their own one. Primer gun with 2.0 setup, sprays very nicely.

Dinitrol underbody wax is ace but it should go ontop of normal underbody stuff. Have used their exterior wax, fells very good, does have a certain life like all waxes (will dry and ned re-doing if not stripping off) - think it's 4 or 5 yrs.

kiwicar wrote:Hi
I am a bit traditional and would go Red oxide, or something like the eastwood etch primer http://www.frost.co.uk/eastwood-grey-se ... 946ml.html .
However anything intended for marine use below the waterline must be worth considering as the stuff must stick and seal very well to work in that environment. Also being non-cyano you will be able to apply it without killing yourself.
Best regards
Mike

well survival is important haha! Red oxide and marine stuff is looking pretty good at the moment.

Hi
Once I have the rust bullet crud scraped (flicked) off my chassis this is what I think I shall do, how about keeping me posted
Best regards
Mike

kiwicar wrote:Hi
Once I have the rust bullet crud scraped (flicked) off my chassis this is what I think I shall do, how about keeping me posted
Best regards
Mike

will do mate, I only started it the other week (only had the new shell a fortnight) but getting on with it pretty well now. Going to be buying a rollover jig shortly which should help massively. Havign thought about it I am pretty good with a brush so probably use the marine stuff undiluted but put on carefully.

Going to go with red oxide aerosols on the bare metal itself because they are readily available and go on nice and even.

Using a couple of wood chisels (for the thick crud) and an angle grinder with those layered sanding discs, £13-ish for 8 off ebay (or £12 each from robbing B&Q!!!) to get it down to bare metal. A lot of work by hand but the finish is great and it's the cheapest option.

Also, I've been keeping all my scrapings/sandings etc so I can weigh it to find out how much crap I've taken off the car, seriously it's already a couple of kilos worth!!! The far back corners of my MG had almost 10mm of thick black gungy crud/sound proofing ... and it's all over the place even under the dash!!!

I'd start with a decent acid etch primer - it only needs a mist coat, so practical with aerosols.

DaveEFI wrote:I'd start with a decent acid etch primer - it only needs a mist coat, so practical with aerosols.

rather than the red oxide or as well as (before)?

Upol does a good etch primer called acid#8. Personally I have never found red led any use outside industrial applications where its lathered on. If you want a protective layer then use a zinc primer, basically cold galvanising but for performance you might not want that since its heavy. Other than that an etch primer and chassis black is what your after. I would still use a good stonechip in areas that get hit with stones though other wise your going to have to keep on top of the paintwork to stop rust. None of it is going to work though if you don't get rid of the original rust in the first place.

Ok had the car up on the rollover jig for a week and made really good progress removing all the gunk and stonechip etc. There isn't any major rust areas, but where there are, and it won't all come off with a snader/grinder, would it be ok to use one of those rust treatments before I spray?

Upol Acid 8 every time for me.
Not that cheap but you get what you pay for.
I truly wish that I had never put underseal on my wagon as it is a piggin nightmare trying to work underneath and not get lagged in it.
Primer, paint, jobs a good un

P

Right, sorry to resurrect and old thread but I'm looking at doing the Skyline underbody in the coming weeks. I'm not quite sure on the correct order for underbody prep;

1. Etch primer mist coat OR red oxide
2. Seam sealant
3. Grey primer
4. Some form of underbody sealant/epoxy etc. over everything
5. Stonechip in areas needed (arches etc.)
6. Topcoat (black)

Is that right?