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to stone guard or not to stone guard?
Posted: Tue Nov 04, 2014 10:42 am
by evonaut
just gauging opinion on the provision of stone chip protection......
my car, the subject of a full restoration, is nearly ready for priming and painting, and now i have the decision to make as to whether i stone guard or not.
considering that i will be only doing about 1000 miles a year, of arid super dry motoring, i'm thinking not, for authenticity as well as that much more satisfactory feeling when viewing the underside of my car. i am opting for 2 pack paint which is a fair bit tougher than cellulose too.
the body shop have offered a fairly smooth finish version of stone guard and they are preparing a sample for me to view next week.....
i have spoken to the extremely helpful mk2 cooper s registrar from the MCR, and he has suggested not, and then applying a clear protective product after painting.....
your experienced expert views and product suggestions would be very welcome
many thanks
evonaut
Re: to stone guard or not to stone guard?
Posted: Tue Nov 04, 2014 11:01 am
by mk1
Personally speaking I would never fully restore a car & not stone chip the underside. Not a great big thick Rhino hide blathering of textured stuff, but a good protective layer of smooth, just where it will do some good.
However, I have never had a car that did 1000 or so miles of super dry motoring a year. All my cars get used regardless.
So, in your case I can't see what is wrong with stone chipping, but maybe it's not really necessary in your case.
Re: to stone guard or not to stone guard?
Posted: Tue Nov 04, 2014 11:09 am
by evonaut
thank you Mark
to be honest, i would love to use the car much more often but the classic car insurance i'm opting for limits to only 1000 miles per year. considering i only do about 5k per year anyway, i thought i might as well make the 1000 dry ones! in reality, the 1000 miles will probably be used up in the first 2 months come rain or shine! its been 27 years since i drove my mini, and i can't wait to get behind the wheel again!
i'm keen to see the sample that they prepare for me so I can make sure its not a rhino skin blathering. i could be easily swayed if the sample is right!
cheers
evonaut
Re: to stone guard or not to stone guard?
Posted: Tue Nov 04, 2014 11:33 am
by Pete
The factory applied stone guard under the wheel arches, why not just do that? One thing I don't like is Dinotrol/Waxoyl applied over perfectly good paint, just looks horrible, collects flies and muck and doesn't really do anything on a lightly used car. If the paint's on the metal properly you shouldn't need it. I remember viewing a Mk2 S years ago that had Waxoyl spread all over every inch of nice fresh paint in the boot and in the engine bay!
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Who's seen cars fully stone chipped inside on the floors? I have!
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You can go too far.
Mini Machine used to do the underside and outer sills in smooth stonechip, which looked fine.
Re: to stone guard or not to stone guard?
Posted: Tue Nov 04, 2014 1:19 pm
by swifty
I've just restored a mk1 S and a mk2 Cooper and have stone chipped the underneath on both cars . I've then painted the stone chip in colour and lacquered . It looks great and it will last . Before I painted I gave the stone chip a good key up with a red scotch brite . I've found over the years that the stone chips that dry ultra smooth seem to be more prone to the paint cracking up on them . Gravitex is what I've used for years .... Ken
Re: to stone guard or not to stone guard?
Posted: Tue Nov 04, 2014 5:38 pm
by evonaut
thank you.
food for thought.......
Re: to stone guard or not to stone guard?
Posted: Tue Nov 04, 2014 6:48 pm
by STG95F
I always leave with no stone chip if its a show car .i think it looks a lot better
I use Rust Bullet ( not cheap but its amazing stuff) on the underside as well on the top then prime and 2k top coat
Just done my 59
Re: to stone guard or not to stone guard?
Posted: Tue Nov 04, 2014 7:05 pm
by Chalkie
Personally Id stone chip it with the smooth stuff aslong the paint under the stone chip is fine
1000 miles a year super dry weather that when stone get kicked up
when its wet not too bad and in the ice i doubt your car will see that but for peace of mind id stone chip it
(I am on my car cause ill use and abuse it)
Re: to stone guard or not to stone guard?
Posted: Tue Nov 04, 2014 11:17 pm
by dgear1984
Stone chip and painted over body colour
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Re: to stone guard or not to stone guard?
Posted: Wed Nov 05, 2014 2:00 pm
by nick@dunsdale
if your car is down to the metal on the bottom side i would use a high quality epoxy primer on the bare metal
doesnt really matter if it has paint on the underneath you can still apply epoxy primer
Epoxy Primers are dedicated to provide the best possible durability and corrosion resistance.
http://uk.ppgrefinish.com/en/products/c ... t/primers/
.
if it were me i might do the wheel wells with smooth stonechip product and paint the underside with epoxy being the base layer. I would probably still take a sander to the stone chip and remove any texture you can flatten it quite easily, though not so easy on bits where there are ribs etc
to be honest though there are very few if any products i.e. stonechip that are flexible most of them cure to hard finish, years ago renault used to make there own branded stonechip product and it was very flexible almost like thick coating of rubber.
The reason i am rabbiting on about primer's is the base layer is the most important layer as a good mechanical bond between the product and the substrate is most important particularly in vulnerable areas
Re: to stone guard or not to stone guard?
Posted: Wed Nov 05, 2014 2:50 pm
by Smiffy
Use thinners in the stone chip to get it smooth.
Re: to stone guard or not to stone guard?
Posted: Wed Nov 05, 2014 3:50 pm
by evonaut
thank you all for your expert and yet varied advice.....
my decision is close and based on advice form the body shop, restoration coordinators, product manufacturers and of course your expert selves.
the shell is down to bare metal although it has a very thin etch primer to prevent corrosion whilst being worked on.
i'm opting for a 10% thinners spray coating of u-pol gravitex plus. This is suited to bare metal or etch primer and with a low pressure in the gun will give a smooth finish of approximately 100-150 microns so the detail will be retained. It is ideally suited for overpainting with a 2 pack paint finish on suitable primer.
I will of course wait to see the sample that the body shop has promised before making my final decision, and of course photos to follow!
thanks again
adam