Opinions on POR 15, zinc powdercoat or epoxy as a primer.

[fly-s30]

Hey there, I am restarting a project after some considerable delay, and the first thing on the agenda is body work.

Most rust has been removed and repaired, though existing damage to quarter needs to be looked at among others.

Sandblasting is the treatment Im going for to remove paint and surface rust that has inevitably come up, but currently still unsure as to what post-blast primer is going to go on.

Options are:

A: POR-15

Local paint shop recommends it...and luckily enough stocks it on the shelf  Looks good promising, but I personally have no experience with it.

 

B:Powder coating

A place around the corner that does zinc powdering on a whole shell in grey, black or red for $450. Its sprayed in the oven, then baked. Supposedly gives a very hard coat and penetrates the steel as a good preventative to rust. Almost like what manufacturers do these days.

 

C: Epoxy

Ol' trusty, and seems a favourite for those in the industry, so they say.

 

 

Questions for those in the know:

Before blasting, is it worth while doing rust repairs, and metal finishing? Ideally my preference would be to smooth body by hand rather than fill, albeit within reason.

 

If using POR 15 system for the underbody area, does it get used in combination with other systems? What, if any, are the compatibility issues with this? Can it be applied to the whole shell?? Touch ups? Can it be welded over?

 

Powder coating zinc? With this treatment was told repairs are to be done as per norm, then once welded, just touch up with zinc pressure pack.

 

Epoxy. Once set does it get in the way of the bonding of metal wiping? Is it weld through or are there other products for that?

Is it a reliable rust barrier/preventative?

If not, what can be applied over as a preventative for areas such as rockers, wheel wells, gutters, cowls, window frames? etc.

And in what sequence ie: blast, primer, protection, topcoat, more protection?

 

Any advice is appreciated, as this is not my my area of expertise.

Any alternatives not mentioned?

 

 

Thanks in advance.

 

[Sirpent]

Go polyester

 

Theres a sticky partial write up I did and thr good Rev will vouch for it.

 

Cheers

 

John

[fly-s30]

Any ideas on controlling rust in areas such as the pillars, and front quarter structure, inner rocker, door internals?

Pillars have no access and some areas need protection but cant get a spray gun in there.What to do in these instances?

[reverendzed]

You can get an attachment (like a hose with a nozzle) that will go on the end of a venturi type spraygun where you can spray a variety of materials (I wouldn't go with fish oil or anything as it stinks and the smell never goes) I've used a lanolin type product which had good write ups, however you won't really see the benefits for 10+ years (to see if it works!)

Rev.

[fly-s30]

So what are your opinions on the options above reverend? Epoxy? POR? Powdercoat?

[mossy]

I'm near the finish of a complete resto and after sandblasting I used KBS coatings on the underbody and inside including taking the skuttle off and painting in there also.

[handsandwhich]

 

A: POR-15

Local paint shop recommends it...and luckily enough stocks it on the shelf  Looks good promising, but I personally have no experience with it.

 

 

 

 

Lucky for who, you or the shop?

 

I would not use por15/powder etc straight after blasting, unless you have done all repairs to the shell beforehand but the reason for blasting the shell clean in the first place is to remove all paint and show you any problem areas that might have been hidden under the paint/bog in the first place.

[reverendzed]

if anything you just want to throw a coat of etch primer over the car after blasting so that you can sand through it and weld etc.  You can't put POR15 on a the car and then hope to spray over it, the chemical makeup of Por makes it impervious (unless you dust coat it at exactly the right point in its curi ng process) thus rendering a topcoat impossible.

 

If you etch which will hold off any surface rust, do your repairs sand and then go with the Polyester you wont have any probelms with your topcoat.

Cheers,

rev

[Sirpent]

If you etch which will hold off any surface rust, do your repairs sand and then go with the Polyester you wont have any probelms with your topcoat.

Cheers,

rev

 

Sorry Rev,

 

But Polyester and etch primer don't mix, don't like each other, polyester is a self etching (So to say) primer / filler which works either directly over bare metal or polyester filler work, not over an etch primer base see page 2 "Special Note"

 

http://pc.dupont.com/dpc/en/US/html/visitor/common/pdfs/b/product/sph/SpiesHecker/3508_06.pdf

 

What I would suggest if the blasted shell is prepped quickly is to put a double coat of Polyester over the entire shell in and out, this will seal it, dent and body work can then be done with final filler work which can even feather onto the polyester without fear of shrinkage later, from here a dry 240 grit sand of the entire surface can be done for final finish paint area's, I would then load 4 additional heavy coats of Polyester over all final paint panels, POR can then be applied to the lower pan inner and outer and wherever else required.

 

Final block sanding is then completed to the polyester area's, DRY never WET !

 

In my case I will be applying a final fine Hi-Fill coat pre paint, but as many US rod shops do, you can apply your final color/clear coats directly to the poly if desired.

 

This would knock back a lot of tedious use of multiple substrates and lock the shell up quickly and safely after blasting.

 

Cheers

 

John

 

[fly-s30]

Lucky for who, you or the shop?

 

I would not use por15/powder etc straight after blasting, unless you have done all repairs to the shell beforehand but the reason for blasting the shell clean in the first place is to remove all paint and show you any problem areas that might have been hidden under the paint/bog in the first place.

 

Yeah lucky for the shop!

Most of the repairs are done, so anything that will come up will be minimal rust wise, other than bogged areas.

 

No opinions on the powdercoat as yet?

If it etches in to the steel like a polymer, wouldnt it be a superior coating to the polymer, being that its zinc? And zinc is exactly what is used in hot dip galvanising. We have all seen structural steel popping up on houses in beachy areas and it shows no sign of corrosion.

After blast, any protective coat would need to be applied quick smart to reduce the chance of corrosion, and the product is only as good as its coverage.

From memory, powder coating is electrostatic? Ferrari uses that system on its body's 

 

Powdercoating Pros: Covers well, Baked in- no moisture, bakes hard, easy to sand

Cons: Bakes hard, cant do it at home- higher costs, unknow long term results?

 

Does this sound correct?

 

Oh yeah and FYI this is from Comet powdercoating in Dandenong opposite Mikes gym/ Dohertys

[handsandwhich]

 

Maybe due to my lack of knowledge on powder coating a car but I cannot see many benefits to doing it.

 

I get alot of things powder coated, on a weekly basis and all I can say is if there are any imperfections like runs or orange peel or dust trapped underneath, it is extremely hard to fix without stripping the whole area and starting from scratch.

 

Scratches and chips also are hard to fix/disguise, but then again, this can be said for doing a metallic/2pak paint finish as well.

 

To me. It Would be like trying to do repairs on the car after it had been painted. Hence the reason why I said I would not do anything except put the car in primer after sandblasting.

 

I know you said most repairs are done but to be honest, you will only truly know what lurks beneath after you blast the shell. You can still e-prime the shell straight after blasting and then powder coat over that at a later date if you still want to go that way.

[fly-s30]

Scratches and chips also are hard to fix/disguise, but then again, this can be said for doing a metallic/2pak paint finish as well.

 

To me. It Would be like trying to do repairs on the car after it had been painted. Hence the reason why I said I would not do anything except put the car in primer after sandblasting.

 

I know you said most repairs are done but to be honest, you will only truly know what lurks beneath after you blast the shell. You can still e-prime the shell straight after blasting and then powder coat over that at a later date if you still want to go that way.

 

This IS a primer, which is sandable. This is not a top coat. You might have misunderstood.

Does that change anything?

[Sirpent]

Maybe due to my lack of knowledge on powder coating a car but I cannot see many benefits to doing it.

 

I get alot of things powder coated, on a weekly basis and all I can say is if there are any imperfections like runs or orange peel or dust trapped underneath, it is extremely hard to fix without stripping the whole area and starting from scratch.

 

Scratches and chips also are hard to fix/disguise, but then again, this can be said for doing a metallic/2pak paint finish as well.

 

To me. It Would be like trying to do repairs on the car after it had been painted. Hence the reason why I said I would not do anything except put the car in primer after sandblasting.

 

I know you said most repairs are done but to be honest, you will only truly know what lurks beneath after you blast the shell. You can still e-prime the shell straight after blasting and then powder coat over that at a later date if you still want to go that way.

 

You are over complicating things, use the KISS method, keep it simple stupid (No offense) powder coating was invented for industrial applications, not the fine finish applications associated with the auto trade.

 

What ferrari and other makes utilise these days is NOT powder coating, it is electrostatic primer application, there is a vast difference between the two.

 

John

[handsandwhich]

 

Hey I ain't the one contemplating using a zinc prime powder.

 

I just can't see it working on anything other than perfectly straight panels because it would just be too hard to do any kind of repairs to after the fact. I don't know how effectively you could use a hammer and dolly on any powder baked surface, not too mention how would any type of filler cope with being baked in an oven at around 200+ degrees? Let alone stick to a powdered base.

 

You have your shell on a rotisserie fly-s30? Then I will just tell you what I did to mine.

 

Had the shell blasted with medium/fine garnet, turned the shell over myself so there was no mistake or chance of anyone "accidently" dropping it. Then had the same place etch prime the shell straight after blasting so as to stop any flash rusting.

 

This then gave a good base for my panel guy to do any repairs to the shell and be able to take it to bare metal again as required without too much headache.

 

I also brushed 2coats of por 15 on the underside of the shell to help protect from road debris and painted on a rubberized paint over the por for added protection and sound deadening.

 

[handsandwhich]

 

 

 

 

 

 

 

[fly-s30]

That looks great! Can you recommend your blaster? Mix and match like what you did sounds like the way to go. Epoxy/POR

How long ago did the primer go on?

Is the car driving? If so, how well did the underbody treatment fare to road use?

[handsandwhich]

That looks great! Can you recommend your blaster? Mix and match like what you did sounds like the way to go. Epoxy/POR

How long ago did the primer go on?

Is the car driving? If so, how well did the underbody treatment fare to road use?

 

Mine was done in Thomastown, don't know if this is too far away from you but I can give you the details if you like.

 

Whoever you choose to do it, they really need to know what they are doing and have experience with doing older cars as well. If they put too much heat and hover in the same area, you can get warping of panels or stenciling showing through.

 

Even saying that, I did not do the inside of the roof and told him to only very lightly do the top of the roof as the pressure can put little dents in the roof. I also would not risk doing the bonnet for the same reason due to how large/thin they are.

 

I use/used 3m brush on sound deadener for underneath and I like it because you can put it on as thin or thick as you like and if any comes off due to jacks or rocks rubbing, it is so easy to just brush some more over it.

 

Car has been painted for just over a year now and it is driving (not registered, but driving).

 

 

 

 

 

 

 

 

 

 

 

[fly-s30]

Damn! Clean and simple but modern. The new headlights give the front end a sparkle.

Im taking notes for what to do and parts in need. 

3M is pretty dependable stuff.

Not topic related, but is that a diff and chassis rail mod? Is it engineered?

[handsandwhich]

Not topic related, but is that a diff and chassis rail mod? Is it engineered?

 

Well spotted. The rail is modified to fit in the overkill r230 diff and the bracing/fuel tank mount you see is to mount the battery box on top of the fuel tank as I deleted the spare wheel well.

 

Car is just about to go through engineering, just tidying up a few little things.