Making webpage for resto/paint issues

[a7dz]

I have not seen it fail when installed by their directions. By this I mean clean the areas with their degreaser (Marine clean) followed by Metal Ready then apply POR 15. I agree that I have had it come off of areas that were not treated in that manor. Good thing too. Matter of fact it peels off in sheets. Escalon and Beandip have both had this on their cars for several years with no failures. One of us knocked a can over and four years later we still have the POR 15 on the drive way. Sand blasting, grinding pressure washing and the North West weather have not phased it.

By the way all three of us run this in the wheel wells of our cars. Still looks like we just applied it.

I think I will pass on stripping it off.

[JimmyZ]

The abrasion resistance and durability of the paint is not to be questioned. It's awesome in that respect.

What's happening underneath the stuff is what I'm getting at.

I recently stripped my 240 and saw metal that just 14 years earlier I had seen. The conditions in which my car was painted were horrible when I was in my early twenties painting in a carport. Amazingly there was very little sheet rust growing underneath the paint. (Just a few spots here and there) I had prepped the metal well.

Two or three years ago I took the Z off the road to do frame rails and floor pan replacement. This time I had a garage and much nicer equipment. I know how to prep metal but instead sandblasted and used POR's metal ready.

Maybe it was a bad "six pack" of POR pints I ordered. Maybe the batch of POR metal ready was made too diluted at the factory. Whatever the case, two years went by and between restoring a mustang, building a plane and everything else the car had set outside covered by a tarp.

Water had set on the floor pans for a few weeks here and there so I wasn't surprised to see rust developing despite being properly POR'ed. What really got my attention were areas that stray Aircraft Remover stripped. The areas had been properly covered with POR and looked fine on the outside but there was a fair amount of sheet rust growing underneath. (More than my 14 year old paint job had) There's something wrong when cheap epoxy and Centari enamel do a better job over 14 years vs a wonder product in two.

Maybe it was just a bad batch. I used every can within two days or less and applied their metal ready exactly per instructions. Only small sections were sandblasted prepped and painted the same day.

I still like the idea of POR but somewhere along the line this consumer got jipped.

[a7dz]

Jim;

Using POR 15 is a three step process. Every set of directions I have received has stated the same thing. Clean, etch, paint.

With out the "Marine Clean" cleaning process I have seen the same thing. You MUST clean any surface that POR goes on with Marine Clean then Metal Ready. Otherwise you get what you are describing. There is more to the cleaning process then just degreasing the surface.

One of us used Marine Clean on a set of polished aluminum wheels so; he could paint the spokes black. The wheels ended up completely flat etched surface if you will.

Our distributor up here in the North West is very clear on the process. Sorry to hear about your experience. I too would be very weary of the product as well under those conditions.

I was told at an automotive paint store that Marine Clean is not necessary. Glad I ran across the distributor before I went to all the work to clean and prep the metal wrong. Needless to say I have not been back to that paint store.

[JimmyZ]

Really, I'm not trying to be argumentative or anything but I know what I saw and what I've read.

I just yanked the instructions from the 'net.

http://www.por15.com/SUPPORT/POR15FAQ/POR15TECHNICALINFO/tabid/178/Default.aspx

The main instruction page doesn't mention marine clean though I imagine it does the same thing as PPG's DX579. (It just skips to the metal ready bit) Marine clean should be have some acid etching properties and be heavier on detergent aspect. Detergent is used so that there is no barrier between the next acid (DX520 or marine clean) and the metal. Marine clean can and should be used for absolute certainty but if the metal is freshly sandblasted with clean air/media degreasing is not an issue.

On another page they talk about the four step process but look at what they are starting with... Some nasty metal.

http://www.por15.com/4STEPSYSTEM/tabid/187/Default.aspx

My stuff was clean, freshly sandblasted metal. PPG will tell you that you can skip to DX520 without using DX579 if the surface is clean. This is why one guy told you you didn't need it. My PPG place sells POR which is interesting.

Here's a snipit copied from POR's website... same page as mentioned above.

http://www.por15.com/SUPPORT/POR15FAQ/POR15TECHNICALINFO/tabid/178/Default.aspx

To coat smooth metal surfaces:

Use POR-15 METAL-READY to prepare surface before painting. Surface must be dry and free of grease, oil, or other foreign substances. Use of 'rust converter' products is not recommended as they may affect bonding of POR-15 to metal. POR-15 likes to adhere to surfaces with 'tooth' rather than smooth, glossy surfaces.

My understanding is that you can acid treat if the surface is clean. Marine clean makes absolutley sure that this is the case but is not needed in situations where the metal is already clean.

I'm turning in dude,

Time to count Z's

DX metal treatment.pdf

[JimmyZ]

Awww jeeez,

I just had one last thought to jot. The paint by itself is completely amazing in it's durability and everything else you could expect from a paint except it failed in one area...

In two years time I had more rust develop underneath the paint than 14 years of regular paint weathered.

The directions say "two coats minimum" when what they should say is "apply four to eight coats to be absolutley sure".

That's all I want to hear from them. Two coats minimum says to me that two coats is enough to get the job done. Works for bases, clears... why not this stuff?

I know the metal prep was acceptable but the # of coats could have been a lot more and maybe I wouldn't be red eye'd typing away with a Z buddy in some other state/country!

Nite

Jim

[EScanlon]

Excellent point Jim (a7dz).

JimmyZ, another couple of items make me wonder if you followed the instructions.

You mention,

Only small sections were sandblasted prepped and painted the same day

Since the instructions clearly state that the metal should be completely dry after degreasing and etching both, and to NOT let either substance dry on the metal (they both get rinsed off), even taking Florida sun into account...that's a mighty short window.

You previously said

I religiously used their metal prep after having sandblasted the metal them applied two coats (spray). It seems that you really have to put the stuff on thick or it will rust. (Try 4-5 coats min.) In their advertising the talk about a 1000 hour test under salt spray but look at the fine print. The thickness used for the test was a whopping 100mils!

Based on that, I would surmise that you thinned the POR with ...??... Even POR's instructions state to not thin it more than 5% per volume, and then using their special thinner which, from personal experience, is really still too thick to spray out of a standard bottom feed gun. Now supposing you used a gravity feed gun, your suggestion of 4-5 coats and comparing that with a "whopping 100 mils" tells me that at best each coat of yours topped out at ... 15 mils or so (and that's presuming you painted THICK).

So at 30 mills (.030" or less than 1/32") of thinned and sprayed POR you then allowed water to pool...in Florida, with a presumed higher salinity to the rain than in Kansas or even 100 miles inland...and

Whatever the case, two years went by and between restoring a mustang, building a plane and everything else the car had set outside covered by a tarp.

Water had set on the floor pans for a few weeks here and there so I wasn't surprised to see rust developing despite being properly POR'ed.

Even you mention

It took about two years for it to show. Mind you, these parts are constantly exposed to water, sometimes salt water.

I'll disagree with you regarding "being properly POR'ed", per your own commentary.

It seems that if anything, you proved how well it works EVEN when you don't follow the directions AND you stack the deck against it.

As far as Stainless Steel floor pans, you don't mention which grade of Stainless to use, nor where or how the average garage mechanic is going to procure the specific welding wire and flux gas for welding Stainless to Carbon Steel. Nor deal with the other problems and technical experience needed to do the job properly.

Then you mention

Getting floor pans to fit perfectly against your cutout is next to impossible so epoxy prime then apply 3M's Fast'n Firm body caulking. It is ready to be painted in 30 min after that."

Does that mean you don't advocate a complete continuous weld because of the difficulty of fitting the repair piece? How do you propose to restore the strength back to the floor pan?

Sorry, but that's just too many short cuts taken for me to give much weight to the rest of your advice.

You've apparently had some experience, but you're apparently self taught. Nothing wrong with that, but it's easy to confuse an apparent lack of failure as being successful.

Please don't misconstrue this as being a flame war, it is not. There are several of us here on this board that have worked on numerous vehicles over a range of years. You've done a lot of good work summarizing information, but please note that what you've posted on your site is only YOUR view, whereas here we've all contributed AND discussed.

I strongly urge you to take advantage of the search engine here and do some reading of all the posts that precede your joining us. I think that you will benefit and hopefully will stick around and benefit US with your viewpoint.

2¢

Enrique

[hls30.com]

I traced the few rust problems I have had under POR to an application problem. Here in South Georgia(probably in most of FLA as well) the Humidity is normally above 97%, When I prepped for and applied POR 15 progressively as the day warmed up, I had issues, when I prepped and applied as the day cooled off, I had no issues. Condensation was forming from the warming air on the cooler metal-I could not see or feel it, but I have proof it was there. There is generally a 20 degree range of temperature during the day, I kept the car in a shut garage over night, and generally got started after 8am by opening the door. I kept the car in the garage(out of the sun and the breeze) and I noticed the car was cooler than the air as I worked on it. Even applying the treatments helped keep it cooler than the air from evaporation(Even at 97% humidity) . As long as the sheet metal was playing catchup temp wise, the potential for an issue was there. Por cures with moisture to an impermeable coating, Surface moisture left over from the curing process can't get out, and will rust until all of the moisture escapes by rusting through the steel, or it runs out in forming rust. With this knowledge, I either apply Por15 to a warmed part, or I apply it in the afternoon(assuming the sun has dropped and so has the ambient temperature. The issues have gone away. This would only be an issue when working with POR in high humidity areas with a decent temperature variation.

I tested my theory by treating two pieces of sheetmetal, both preped outside, and treated with POR as the dawn came up the next morning. Both were stored inside under a running an airconditioner all night, stabilizing the temperature of both and lowering the humidity in the room. The one treated with POR inside got a beautiful glossy coat of POR, the one done outside minutes later with the same brush and the from the same sample of POR developed tiny bubbles almost immediately upon application, indicating a severe moisture issue-even though no condensation was seen. The piece was allowed to reach outside ambient temperature with no enhancement(no additional air circualtion, no sunshine) for almost half an hour before applying the POR15, the sample of POR 15 was covered immediatley between applications..

Will

[JimmyZ]

Hi Enrique,

Yes, I agree no war or anything intended, just good discussion. I knew that saying anything against POR would elicit such a nice response. It does make for good discussion. I'll make this post for the POR discussion then another post for the floor pan mtl. explanation.

I'll explain how the POR products were applied and where I think things may have gone wrong.

On any given day of prep I would start by sandblasting a section no larger in area than 3'x3' (An entirefloor pan or entire front inner fenderwell for instance) Air used in sandblasting was double filtered and 95% moisture free. I've actually laid cleaned parts in the garage for a month after sandblasting and not had any surface rust develop. (Just microscopic stuff of course)

I would wait a few hours for the compressors (25 cfm combined output) to cool then drained my traps/compressors. Before painting POR I applied metal ready and YES I do know better than to let the stuff dry during application. Some panels were rinsed off others were wet toweled. In all cases panels were towel dried and crevices blown free of water. The metal looked like it had been prepped. There was the usual hazy film but not the extremely red/rusty film which betrays the fact that things stayed wet too long.

Unthinned POR was sprayed thru 1.5 tipped HVLP gun in two coats on vertical/irregular surfaces. I brushed the floor pans so that I could work the paint into some welding irregularities. Two coats, sometimes more were applied but usually two coats.

The rest I've written about.

It is possible that there was excess humidity in the air during painting during the FL summer. It's possible that the product was applied to thin to be impermeable. I do know that the Z.phosphate leftover from the metal prep was on the money as far as appearance. The metal was allowed to dry/bake long enough before paint application.

At the cost of dragging this post out too long I'll cut it here.

Jim

[JimmyZ]

Enrique wrote,

Then you mention

Quote:

Getting floor pans to fit perfectly against your cutout is next to impossible so epoxy prime then apply 3M's Fast'n Firm body caulking. It is ready to be painted in 30 min after that."

Does that mean you don't advocate a complete continuous weld because of the difficulty of fitting the repair piece? How do you propose to restore the strength back to the floor pan?

Sorry, but that's just too many short cuts taken for me to give much weight to the rest of your advice.

End quote

Here's a brief semi-full explanation...

I advocate a perfect butt weld if at all possible. (100% fused airtight all around) Realistically speaking, when working with an area the size of a floor pan and trying to contain it to a single sheet a small lap is almost unavoidable. Getting a 0 -.023" gap around such a large area is a real time expenditure.

Let's say that one area of your cutout has no holes but has been thinned by rust. Attempting to butt weld new material (thicker) to the thin stuff will invariably find you burning back the thin edges. A lap of 1/4"-3/8" will work fine. With a lap technique you can avoid blowing holes and simply "drop" the thicker sheet via puddle onto the thinner sheet. If working with thick on bottom you can also build a puddle on the thicker sheet and direct the heat at the thicker sheet so that as the puddle moves/grows the thinner sheet is fused to the advancing puddle. I'll make a video of this when I get a good shade for my camera.

The best/proper way to do it is to fab a new floor pan and do as one of the other memebers of the club posted... Cut the pan off at the rocker panel. Paint the rocker everywhere except use weldable primer where the spot/plug welds will go. It is the transmission tunnel area and the irregular surfaces/contours which I'm reffering to lapping in.

Welding stainless to mild steel is not a big deal. Yes, stainless should be back purged with inert gas but the number of lineal inches of weld laid overcomes the reduced strength. You can use regular ER70xx MIG wire when joining the two. I MIG and TIG weld stainless so I know what one can get away with for each application. Welding stainless for corrosive environments or high heat is quite another issue. Auto sheet metal welding is just one step up from tractor welding in the scheme of things. (Just need to pay attention to heat input/distortion more) The pain of working stainless is cutting it or grinding it. It can be cut/gound with normal tools but the abrasives don't last. I use a plasma cutter then grind the edge clean of oxides.

The back side/half of an unshielded stainless weld will be brittle and have little corrosion resistance. (Grind, sand then paint is the answer) In a floor pan situation look at the length of the weld though. (10-12 feet)

In the strictest sense an ideal finished weld should posess the same metalurgy/properties as the parent material. (Be as strong or stronger, dutile etc...)

One textbook's definition of welding was "The joining of two materials in a matter suitable for the intended use/structure". This second definition is what I'm reffering to.

It's hard to express complete ideas in these posts without writing a novel. I try to be brief and this leads to the need to expound.

My opinion, (And it's just mine, I recognize that) is that using stainless would free one up to focus on keeping corrosion down in other areas during repair. Post repair benefeits are to be had as well. Properly installed mild steel is fine too. It just takes a little more footwork for prep.

my 2c

[beandip]

I have just now read this thread from the beginning . I do have to add that , I have used POR-15 products in there many forms . I have followed the instructions and prepped the metal as was directed . I have had the stuff on my Z now for almost 4 years and have a zero failure . The only place where it didn't perform was on a surface that I hadn't prepped and I didn't want there any way. This was on a primered fender , where it ran down from the marker light hole when I was BRUSHING the POR on the inside of a rear fender. I let it cure and was going to start sanding the panel in preparation to finish. Instead of sanding it , it lifted off like plastic rap , but only up to the opening in the fender where the metal had been properly treated. I have heard of other failures of POR by members of this web site , but after asking them how the surface was prepped they took shortcuts . Simple Green WILL NOT PREP THE METAL CORRECTLY , THE SAME WITH ANY LAQUER THINNER OR ACEATONE ! As was mentioned before , I was going to spray some rattle can paint on my turbine wheels after I polished them and I wanted to get the metal REALLY CLEAN . After masking the polished metal , I sprayed marine clean over the wheels from the back side and rinsed it off. Let the wheels dry in the sun and then the sprayed the rattle can paint . When I removed the masking tape the MARIENE CLEAN had etched the shine of the polished metal I had just finished. !! I had to re-polish . My wheels have 40 spokes on each wheel . So my point is use the proper recommended preparation materials and you wont have any failure . Of course moisture is a BIG FACTORE with applying POR . The paint is water reactive and if there is moisture it will react and foam will occur. Be sure all is dry. It is not recommended to apply POR on a rainy day , just because of the high humidity will cause the paint to cure too quickly. I live in Portland Oregon we have rain 9 months a year here . Again after 4 years I have zero failure and I drive my Z . She is no garage Queen. Do I use POR-15 ? YOU BET ! Do recommend it ? ABSOLUITLY ! Do I have any connection with the company ? NO MY 2 CTS. Gary :er-mm: