My '72 P6 V8 is back in use on UK roads and once again wearing its silver on black 'K' plates!

mrtask

Well-Known Member
In my continuing quest for speed I located another nice void in my bodywork, this time in the O/S front wing. The paint had started to bubble some years back. A quick poke revealed that the filler beneath was swollen. Boy, so much filler too! The stiffener behind the wheel arch is a known moisture trap. My wing had rusted to the consistency of breakfast bran flakes, and the stiffener behind is similarly corroded. Yay!

front-offside-wing-speed-hole.jpg

Excuse the poor photo, my not-so-smart-anymore-phone doesn't cope with bright sunlight too well.
Good thing I got hold of a NOS wing the other month, eh!
Is it normal that the top colour coat easily peels away from the primer beneath, like a thin plastic film, once you slice through it? I thought there would be greater adherence between the layers of paint?
 

cobraboy

Well-Known Member
I bare metalled my whole car and the paint was stuck to it like it was part of the structure. Every panel had weird creeping spiders web finger like rust
stains under the paint, but the paint held on till the last.
 

mrtask

Well-Known Member
Cobraboy, what did you use to take your panels back to bare metal? What would you suggest I use to prepare my spare set of doors and wings for paint. I also want to go back to the bare metal, but without f**king the surface of the metal up. I can work one panel at a time, outdoors, and I expect my neighbours will be upset if I use power tools and make lots of dust at the end of their gardens, so I'm thinking perhaps paint stripper rather than abrasives? Does anybody know where I can get good old fashioned stinky toxic paint stripper? Is it called aircraft stripper? I've been quoted eighty notes per panel for soda blasting, but have heard that it can be difficult to completely remove and/or neutralise the residue which can subsequently ruin the paintwork applied on top. Anybody here have any experience or recommendations for me, regarding method and materials?
 

unstable load

Well-Known Member
Is it normal that the top colour coat easily peels away from the primer beneath, like a thin plastic film, once you slice through it? I thought there would be greater adherence between the layers of paint?
Only if the paint wasn't properly applied or if there was incorrect preparation in the first place.
It should bond to the layer beneath like the 2 are one.
 

cobraboy

Well-Known Member
Cobraboy, what did you use to take your panels back to bare metal? What would you suggest I use to prepare my spare set of doors and wings for paint. I also want to go back to the bare metal, but without f**king the surface of the metal up. I can work one panel at a time, outdoors, and I expect my neighbours will be upset if I use power tools and make lots of dust at the end of their gardens, so I'm thinking perhaps paint stripper rather than abrasives? Does anybody know where I can get good old fashioned stinky toxic paint stripper? Is it called aircraft stripper? I've been quoted eighty notes per panel for soda blasting, but have heard that it can be difficult to completely remove and/or neutralise the residue which can subsequently ruin the paintwork applied on top. Anybody here have any experience or recommendations for me, regarding method and materials?
I tried paint stripper on the S1 bonnet I acquired, although it was pretty strong nasty stuff it still would not get all the paint off. For the rest of the car I used a 150mm air powered DA sander. It took a long time and used 'several' discs.
I used something like an 80 grit to get through the top coat, and when the first primer coat started to show then used finer grits, maybe 180, down to the metal.
It was a soul destroying job, I set a target of a panel a day to keep sane.
Beware of blasting, I sent the front and rear decks and valances to be blasted as they were difficult to sand and the front deck warped and changed shape. I did not realise this until re fitting after finish paint.
Remember also that I did not have four wings to do as these were new.

There will be dust, I would set up a stand on a tarp, this way you can fold it up and tip the dust into a bin.
I guess you could use an electric sander if you do not have air. Either way there will be noise I am afraid.
 

mrtask

Well-Known Member
During the recent spell of good weather I procured an electric DA sander/polisher and an electric drill, some grit discs and some wire brushes, and set about taking some spare panels back to bare metal. I started with an offside rear door, as that is the biggest hole I've gone and poked in my current panel work. I began with various wire brushes on the inner edges which are too fiddley for the big DA. I found a few pinholes where the latch is mounted and some corrosion from inside to out along the lower bulge of the inner pressing. It will need metalworking.
Lastly I tried out the large DA on the outer surface, and discovered the door has already been treated to a lower half skin replacement. The join is just where the sharp crease should be, so I was disappointed. I imagine that will be very hard to recreate in filler, and my objective this time is to achieve sharp lines, without pillowing or quilting of the paint, ideally with as little filler as possible. I think I might need to obtain a better OSR door.
I moved on to rear wings. Imagine my delight when the NSR, the better of my two spares, turned out to have been drilled a second time to mount the stainless trim lower. The original holes were just covered by the trim. Both rears will need a bit of metal rectification at the rear lower mounting points.
This is my first go at taking paint of exterior panels. The wire wheel in a drill has left marks, or gouges, in the metal. Do I now need to sand those back, or will that be covered up by the primer coat?
I have a NSF wing that was sandblasted many moons ago. It has a dull stippled finish, rougher than where I've used the DA on the first trial door, which comes up much shinier in comparison. Do I need to sand the sandblasted surface to smooth it more?
How fine a grit should I go down to on the exterior surfaces so that the painter can achieve a great finish?
 

cobraboy

Well-Known Member
IIRC I used 80 grit to get down to the first primer coat, then 180 to get that off, then 240 to get to the stage where I gave it to someone else ;)
 
hi mrtask, im doing my doors atm, taking them back to bare metal to respray. this i have done to a whole mk2 ford consul years ago.
i used to work for "The Toolshed" and aquired the tools and a wire brush on a grinder... no, scratched to buggery.
i brought some surface conditioners which were reasonably new back then and this is what ive have been using to take paint/filler off.
They leave the metal unscathed and remove most rust should that be present.
They are known by a few different names like strip discs, paint remover discs and they are (can be suitable for drills) made for different size grinders , mine being a 115mm angle grinder.
They are basically a nylon web impregnated with carbide grit.
There maybe places the cant get to as the are a round disc, but youll be surprised what they can do. just a note if your not careful, a sharp part of the panel may catch it and take a chunk out of the web, unbalancing the grinder but will wear to round again.
i clean the panels with an acid (phosphorus) you can buy off the shelf (metal conditioner) and it leaves a film you can paint/primer and will stop oxidation of rust for a few days too , good if you want to paint a few doors at once
 

corazon

Well-Known Member
Yeah poly strip, or ‘strip and clean’ discs are great.
Having a combination of wheels for the drill and discs for grinder is a good setup for quick stripping. You do still have to be mindful of heating up a localised area too much with panel work.
Check out Norton Blaze discs for grinders, expensive but awesome :cool:

Jim
 

mrtask

Well-Known Member
Thanks for the helpful hints.
I am not going to be painting these panels myself. I was just thinking of prepping them to give to someone who can then carry out the repairs that will be required, and then get them painted. I was hoping if I store them indoors in my heated apartment that they wouldn't rust. Will I get away with not having to apply phosphoric acid conditioner?
I think I'm going to buy a grinder and some of those Norton Blaze discs. Do the smaller discs fit in my drill?
 

mrtask

Well-Known Member
I'm not struggling! On the contrary, on the door the DA went straight through the various coats of white and revealed the mustardy primer in no time at all, and I quickly switched to a finer disc. The gadget makes mincemeat of the paint in a jiffy, and I was at the slowest of six speed settings!!
Where I used the wire wheel in the drill I think I simply pressed too hard. Doh! I only did the parts of the door inner which don't really get looked at, and the same for the areas of the rear wings which are concealed when fitted to the car. My problem is more that I've got the panel or door flat on a table, rather than bolted to or hung on the car. The DA needs two hands and so I need to somehow fix the panels whilst I work on them. I'm not in a workshop, I'm out behind my back yard in front of a disused garage, as far from the neighbours as I can get so as not to disturb everybody too much, doing an hour or two when the weather allows. My work surface is actually a garden table with some layers of bubble wrap taped on top! Far from ideal. I miss my old shared workspace in Berlin where I had a big solid bench, and where I could work when the weather was inclement.
I'm thinking I might need to buy one of those DIYers folding work tables. Anybody got any experience attaching panels to one somehow!?
 

corazon

Well-Known Member
Yeah Mirka do some nice lightweight ones, similar to their air offerings.
I picked up a bargain Bambi silent compressor a few years back so just a gentle hum in my workshop, more like a dentist :p
 

corazon

Well-Known Member

cobraboy

Well-Known Member
Yeah Mirka do some nice lightweight ones, similar to their air offerings.
I picked up a bargain Bambi silent compressor a few years back so just a gentle hum in my workshop, more like a dentist :p
That's the problem with those Bambi compressors, they don't know the words..................
 
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