How to remove drippings in Por 15 engine enamel

[Twan-Sloot]

Hi guys,

I blasted my oil pan, transmission pan and valve covers to give them a fresh coat of engine enamel. So I got the por 15 cad dark blue engine enamel. Prepped the metal and off I went. Paint had a nice sheen and it said on the container that one coat should be enough. So I tried that and it obviously can’t be done in one coat. But in my attempt to do so I got some drippings in my first coat which applied about 30 minutes ago. So my question who of you have used the product and how to fix the drippings.

Wait for the first layer to fully cure and then sand it and put another coat on, or is the por 15 thick enough to cover those drippings with the second coat?

All advice will be appreciated

[Twan-Sloot]

Haha not much people have experience with their engine enamel. Well keep it that way. I wet sanded it all perfectly flat and put on a second coat. This time I didn’t want any paint runs so I put it on thin. Well and the result of putting it on thin is that the paint will show brush strokes. So Por 15 engine enamel gives you the choice between runs or strokes! your choice! I don’t like te product at all. Did everything acording to their instructions but it just doesn’t flow enough it’s to thick. I do believe it is indistructable and rust preventive, the color is right as well. It only doesn’t want to lay down smooth. I think it’s great for the block itself but don’t put it on the pan or the valve covers just doesn’t look as nice as spray paint. Better get the bill hirsch rattle cans.

I’ll keep my pans and valve covers like this now because I do think it’s the best protection for metal and the color is nice and glossy. I’ll put some pics up once they fully dry maybe the strokes will fade a little while curing

[TMoore - NTCLC]

I would have never considered that POR-15 had a correct engine paint, so I was curious to see your results.  I understand that once it is on there, it is a very tough paint.  I have used the Bill Hirsch engine enamel on my projects, and have had good results - a nice, shiny durable finish.  The colors are either an exact match to factory original, or the products have been used for so long that the Hirsch colors are considered the de-facto correct colors for restoration.

Post some pics - I am sure that your finished product will have long-lasting results.

[Twan-Sloot]

yes it is a long lasting result once cured, but it only cures when you put it on the engine and let it bake on there. it will stay soft if you just let it sit. after looking at another container of POR 15 engine enamel I think my first can might have been a bit dried up already when I opened it or something like that because this can was more fluid.

here you see the results on the horizontal parts it turned out pretty great on the vertical parts pretty horrible urghh, Out of laziness I want to let it sit the way it is, but I am afraid I will regret that. Leaning towards getting it off now while still removable and paint with a VHT rattle can to get a smooth result.

[Roger Zimmermann]

I would never apply paint on sheet metal parts with a brush, only with a spray gun. Once install, when the paint is getting hard, you may sand it (there is some space) and buff it.

[chrisntam]

Call the manufacturer and talk with tech support.

[76eldo]

I agree with the other posters. Brush paint should only be used on cast surfaces like heads or blocks. For tin parts like valve covers or an oil pan the Bill Hirsch spray paint for Cadillac is the best bet.

I'd re blast the parts and start over. It's going to be much easier this way.

Frustrating but the best way.

[79 Eldorado]

Just adding some of my experiences with POR products:

The typical POR15 black for frames, rust, etc can absolutely be brushed on without leaving brush marks later. It just wets-out very well so I can understand why someone may try it with their engine paints.

I used quite a few of the POR products in the past and one thing I always had some issue with was their main pitch was rust preventative paint but it was never clear to me if ALL of their paints are paint-over-rust and have the same resistance. I noticed I was making some "leaps" with what they wrote about things they never really came out and said about other products.

I did buy some of their engine paint long ago. Their big marketing catch was much higher quantity of solids compared to other paints and thus the fewer coats necessary. I seem to recall though I really limited my use because the temperature resistance wasn't as high as some other products and my biggest issue with engine paints had always been area near high heat. That part may have been my perception but anyway I tended to favor VHT products and good surface prep for things which I know will see heat.

Recently I started to use the Rust Bullet products. If you dig through the data they have in their reference areas there is simply more data there although sometimes difficult to find the relative reference you may be looking for. As an example Rust Bullet posted some testing results of one Bridge Authority (BA) where they compared the BA's best known solution to both silver and black versions of Rust Bullet. As I recall the silver did slightly better and silver was as good if not better than their best known solution. I don't think you can find any relative comparison within POR products within the POR family of products. As well I noticed that Rust Bullet maximum operating temperature seemed quite high for a product not really focused on temperature resistance. I would need to verify what the can says but I can say as a test case I coated some drum brakes with it and it seems to be holding up very well.

One other observation with POR15 black specifically. It is not UV resistant and requires a topcoat; fades in a relatively short amount of time. As such I painted some parts which I could not clean completely (trying to preserve an original logo) and I didn't wait for the exact window which POR recommends for top coating with other paints. I noticed that the VHT top coat I added seemed to be getting sucked into the POR15 initial coat and the final product did not look as good as I had hoped.

Regarding POR15 removal. Acetone will remove it if you accidentally drip POR15 on something and clean it relatively quickly but partially dried. I haven't tried it for removal of something I purposely painted and let dry. I suspect that could be a challenge. It will completely peel off as a sheet if you paint flexible smooth plastic though. I had what I felt was an ideal plastic container to paint from and I always just let the POR15 dry in that container. The next time I need to paint I just peel out the complete liner of dried POR15 with zero residual adhesion. I do the same with my ice tea mix scoop which I use to transfer the POR15 to the plastic working container.

Scott

[Twan-Sloot]

Wow great wealth of information thanks guys, I think I am going to re blast the parts allthough it’s frustrating but in the end it will pay off. Gonna go with a VHT base coat, then a color coat. Is it also advisable to add the VHT engine clear coat on top of that?

[79 Eldorado]

Twan,
One more thing. I think before I blasted it I would try a power sander after the POR is completely dry (It is difficult to sand after completely drying based on POR15 gloss black). If that works you will need to top coat but you will still have a lot of protection from your initial coat.

As well if this is a part which you only have one of I might be tempted to paint a test piece of something else and try removal techniques on that test part first. POR dries pretty thick so if that gives it some flex when the blaster hits it I think you are still looking at a lot of work. If a power sander can feather out the uneven areas then you just need to top coat with VHT or something else.

Scott

[67_Eldo]

One other observation with POR15 black specifically. It is not UV resistant and requires a topcoat; fades in a relatively short amount of time.

Yup. And that relatively short amount of time is indeed short.

My first attack on the roof rust on my 67 Eldorado was using POR15 and Rust Mort. I not only used POR15 straight from the can -- a little goes a LOOOOOOONG way -- but also as the resin substitute for a few fiberglas patches. The car did not sit outside, so its exposure to direct sunlight was minimal.

Still, I was able to pull sections of the fiberglas and the POR15 off with a pair of pliers in less  than two months. Its color had changed from black to gray and its power over rust was obviously weakened.

I covered another section of my (pitted) top with Rust Mort. As soon as the Rust Mort finished its work (in about 30 minutes), I cleaned up the area and hit it with primer. Six months later, when surface rust was beginning to reappear on the untreated-but-primer-ed areas of the top, the Rust Mort-ed area was still rust free.

21st-century chemistry is nice, but it won't save your bacon without some old-fashioned assistance. :-)

[Twan-Sloot]

Twan,
One more thing. I think before I blasted it I would try a power sander after the POR is completely dry (It is difficult to sand after completely drying based on POR15 gloss black). If that works you will need to top coat but you will still have a lot of protection from your initial coat.

As well if this is a part which you only have one of I might be tempted to paint a test piece of something else and try removal techniques on that test part first. POR dries pretty thick so if that gives it some flex when the blaster hits it I think you are still looking at a lot of work. If a power sander can feather out the uneven areas then you just need to top coat with VHT or something else.

Scott

I was thinking of the same thing Scott, if the por is too thick it will bounce sand right off and sandblasting would be a hard job, I have time in the weekend and will see if the paint is still weak by then. Yesterday I could scratch it off with my nail. So if it is still weak I guess the sandblasting will take it right off. If it is cured by saturday it is probably gonna be a job for the grinder. I personally would like to get the por off all the way because after using it I think the product was designed to protect rusted metal and not perfectly clean metal. VHT on a clean metal base is the best option now in my opinion.

Degreasing and painting has got to be the least favorable job of restoring a classic haha

[79 Eldorado]

There is always some risk when painting over something blasted that there is a tiny amount of rust not obvious to the naked eye remaining. I've had good luck with VHT epoxy primer-sealer. I believe it's an etching primer. The old product rattle can was recognizably purple in color but they changed their can design. Since they changed it it seems to me they left off some description especially on what is their high temp version. I'm not familiar with Rust Mort which 67_Eldo used but the issue described, to me, sounded like either there was residual rust deep in the pores or that most primers are just for prepping a surface and do not offer great protection by themselves. The primer needs to be a primer-sealer to offer protection. If it's an etching primer my limited understanding is it has something in the chemistry to handle the issue of something not visible. It sounds like the Rust Mort did that in 67 Eldo's test case.

There are other products as well designed for blasting. I bought one but have not yet tried it. Eastwood's "After Blast" is the one I have. I also recently used Rust Bullet silver painted on a thermostat housing and then I color painted it with Duplicolor Oldsmobile blue. I would have used VHT as my preference, still over Rust Bullet, but Duplicolor seems to be the only company still selling anything close to Oldsmobile blue   I blast outside and for the housing it was raining and I wanted to finish the job while still doing the best I could. It was in good shape but there was some rust so I hand sanded it and used one of the scotch-brite/ sandpaper flappers on my drill to clean it. I then used rust bullet. About 1 hour later I sprayed with Duplicolor. That was the same thing I did to a rear axle which I was not planning to remove; simply detailing a bit after changing a leaky rear axle seal and rebuilding the drum brakes (so again not perfect cleaning). For the axle I used VHT chassis black primer-sealer over the top of the Rust Bullet for color. The axle housing/ brakes were done over a few days and I did find that if Rust Bullet dries thoroughly VHT had a difficult time biting into the surface. I know because while bleeding the brakes some fluid got on the axle housing and some of the VHT wiped off. Brake fluid is really bad on paint but the Rust Bullet silver seemed to be ok underneath. I just cleaned it and re-sprayed with the color coat.

I guess my point is and I think the point 67 Eldo was making is even after blasting you may want to have something which can handle remaining rust or flash rust which you may not be able to see. The existing POR engine paint may take care of that.

Hope it turns out to your satisfaction,

Scott

[Twan-Sloot]

Well after trying to sand it which didn’t work out well because the paint would crumble, I decided to take it all back to sandblaster.

Took 4 hours in the blaster in combination with two cans of paint stripper, one thing is for sure I did prep the surface right last time. It was a tedious job, but worth it once I have It painted nice and tight. Vht engine primer going on now after a good shower and degreasing.

[79 Eldorado]

Twan,
I think it's good that you at least tried sanding the paint first because if you hadn't you would have been wondering the entire time you spent blasting, 4 hours, if sanding would have been a better idea. I was really surprised to read that sanding resulted in the POR engine paint crumbling. That's probably the last thing I would have expected. Was it just so think that is places it was delaminating or something?

Anyway the runs and droops are gone now,

Scott

[Twan-Sloot]

Well I think it started to crumble because por engine enamel won’t cure fully until it’s baked on the engine. Since I didn’t want to put it on the engine first the paint still wasn’t hard like a rock. That’s why sanding resultid in a unsmooth crumble like paint finish

[Roger Zimmermann]

You may have time now to remove some dents from the oil pan!

[Twan-Sloot]

I didn’t show you guys how it looked before I painted the por 15 on the pan but it was extremely dented because some bubba put a jack under the pan once, it was dented so far in it hit the oil pump slightly. I tried to smash that dent out with a big hammer but it didn’t want to move at all. So I got creative (see attached picture). Put it on a jack stand with a piece of wood in the pan and than dropped the caddy on it haha.
After pressing it 10 times on various places I already was pretty proud of the results.

The small dent that is still left in the front of the pan which you can see in my previous post is hard to get out. It’s on a nasty place of the pan can’t figure out how to apply proper force there.

[Twan-Sloot]

Great results with VHT

[79 Eldorado]

Twan,
How many valve cover bolts do those use? When Oldsmobile went from 10 to 5 on the 350 they were very difficult to seal. The covers don't take much torque before distorting. There were some pieces which looked like shims that helped distribute the load but they are still very particular. Yours look like the ones someone else posted recently where they needed to remove head bolts just to change the valve cover gaskets. I could hardly believe it. If that is the case I wanted to at least mention something a local shop recently turned me on to Permatex's The Right stuff gasket maker. I've never used it on valve cover gaskets but I did use it thinly smeared over a rear differential cover I previously had an issue sealing and on a transmission pan gasket. I would still buy the best gaskets I could but the next time I do an Olds motor I think I will try it on probably the oil pan and the valve covers. That said I'm not certain how difficult it is to remove if you ever need to.

I thought I would mention it because at least I only see 2 bolt holes on one side of you valve cover. What a crappy place for the people designing thins like that to cheap-out-on. I'm curious to hear if others have had experience with it. The local shop does not like come-backs for leaks and they swear by this stuff.

https://www.permatex.com/our-brands/the-right-stuff/

Scott