VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 Por-15 or Corroless for under my 28 Chevy ?

When the weather warm up I'll be ready to paint the underneath ( chassis, running gear) of my 28 Chevy coupe. I've read all the literature on both Por-15 and Corroless and still can't decide which would be better? I'm not going to dissasemble the running gear but will just sand or wire off the rust and then paint most of it together.I'm past the good old days of dissassembling everything and painting it piece by piece. I want to drive this thing before I get too old! I like the idea of a tough black coat for the surface coat on top of the fendersmore than a fancy show quality finish.One question I have about the Por-15 is that if I painted it on first and ten went to paint on their surface UV resistant surface paint, how would I know what was undercoat vrs, surface paint?their both black. At least with the corrless the undercoat is brown?

Scott

Scott
I used Por 15 on the undercarriage of a newer car . It did chip and crack ,and water got behind that stuff and the sheet metal there was a lot of rust formed before I found it.Some pannels were almost ate through.and it was hard to remove what was left.Has any one else run into this? It really turned me off on this stuff.
woody

Hi there

I used Por-15 on my '28 sedan frame and undercarriage. I find it to be fantastic. They are right... the more moisture the better it adheres to rust and metal. It has been 6 years since I did it and it still looks great. Using it on the underside of the car leaves it out of direct sunlight. I also used it on suspension and brake parts on my '63 corvette. It is the best. Oh, I DO NOT work for the company!!!!!

mike

I never did understand why anyone would want to paint over rust! In my experience it does more harm than good, and it is not even close to any original finish from 1928. It hardens to the point where it is nearly impossible to remove, as Woody said, and by not remedying the original problem, it only serves to promote an incorrect restoration process. The worst thing about POR is that it is VERY nasty stuff, health-wise. I have had black Rustoleum primer on the undercarriage (cleaned and wire brushed) of a 1970 Summer driver pickup that has held up extremely well for going on seven years. When it's time to touch up, it will be an easy fix, and if I want to do it right down the road, that will be easy too. Because it cures so hard, POR admits it can not be recoated with anything after it cures, not even POR (I tried it and it peeled off - you can't scuff hardened POR enough for it to hold on).
I have used POR with good results on steel bridge beams over a brook, before I added the planking. I think that is the application it is more suited for.
I'll get down from my soap box now. :rolleyes:

SPEEDLINE

I purchased a 1915 F##d that had been painted underneath with that stuff. They did a lousy job, even painting the carburetor and all lines and fittings. When I decided to redo some of the work I found it was impossible to remove the gook. In some cases it was cheaper and easier to just throw the part away and start with a new one. :p You will never catch me using that product. :confused:

I used Por-15 on the sub frame of my Nova because I could find no paint that would stand up to gasoline. It has not been on long enough for a true test. Dad just used POR-15 on the frame of a '64 Bel-Air after sand blasting. It looks great.

If your not using a product like this, what are you using?

Chris,I have used PPG Dp40 primer and a good enamel on sand blasted undercarriages and wheels for many years with very good results.Its expensive but it stays real good and its repairable.
woody

I'm with AntiqueMechanic! I would never use Por-15 on anything. There are better materials out there to work with, and they are a lot less trouble too. :)

Wow, I guess I never thought of a product being to hard to get off later but that does sound like it could pose a problem? What brand of paint would you guys reccomend using on the underneath? Remember, I'm not dissasembling everything! I don't plan on painting over rust but as I will sand and wire off as much as possible but some little rusty spot may elude me is why I thought a paint that can go over rust sounded good.

Scott
sdakss@aol.com

When I want the car to look correct, I spray 3-4 coats of PPG DP40 also, but I don't topcoat it with gloss black. It has the correct semi-gloss appearance of the original undercarriage paint as it is, it can be repaired easily, and being an epoxy base, it will hold up for a very long time. When using any paint, there are no guaranties when the metal is not sandblasted and properly prepared. :(

SPEEDLINE

Speedline is right about DP primer.It has to be clean,but another thing that will work real good is the oil base primer from a tractor supply store it sticks on moderate rust real well I used it before theDP primers came out.Plus its a lot cheaper.Guys dont laugh I have seen rusty tractors painter with it sit outside for years and still look good.

Any takes on Corroless??

Scott

Be careful with the semi-gloss because that finish is not correct for the early Chevrolets since semi-gloss wasn't invented then. Frames, axles and etc. were all gloss, not semi-gloss. :)

I will have to agree with Woody, also Tractor Supply Co. is a good source for 6 volt battries, battery cables and a lot of other good stuff for old cars.
Por15 seems to me to go on better when applyed with a brush, worked in, and it works better on rusted metal that has been wirebrushed, there should not be any reason to apply por15 on a metal surface that is shiny or freshly abrasive blasted since it is a rust converter. I believe an epoxy primer sealer is better on non-rusted surfaces and when you need to spray. Have any of you had a problem getting the lid off of a partially used can of Por 15? Also it works better if it is fresh, shelf life appears to be short, less than 6 months.

I went with the corolles.I sandblasted the frame on my 42 and sprayed it on.I Painted it with there low gloss chasis black with the sray bomb.This was my first time useing a spray gun and i found it easy to work with and it layed down nice.The same for the black bomb.I cant say how it lasts because im still under construction. Iam however happy with its appearence.