removing old engine paint

[DutchEdwin]

I'm going to paint my engine, 1955 260cu.in. V8. Completely dissassembled it. Everything is cleaned now. I'm going to put POR-15 on it. (took me some time to find it but, yes it is available in the Netherlands where I live price: $32 per pint (= 0.47 liter) ).

I have two questions.

1) what is the best way to degrease it prior to the paint job

I've heard some idea's: using paint thinner, normal green soap, brake cleaner, biological household fet and grease remover, even oven degreaser.

2) There is some old paint left on some parts. If I do not wat to sand blast them, what is the best way to remove this old paint. Sand paper will not do the job

Thanks.

Edwin.

[Norm's Coupe]

Edwin,

If you don't want to sand blast, you can use a wire brush on a drill to remove the paint. When finished wire brushing you can use paint thinner or mineral spirits to degrease.

[48Dodger]

Hot water, simple green,and scotch brite pads. remember to clean the oil galleries with pipe brushes. Air dry the block (compressed air or big fan), paint it, than get some light oil (wd-40) on the cilynders bearings, etc... put a big trash bag over it until you are ready to do the final build. I don't like to use wire brushes if the block is bare ( metal on metal seems to yield metal which can get inside the motor). I myself clean the motor parts first, build the long block, close all inlets with duct tape, then paint. That way nothing gets inside the engine. old spark plugs work good as hole pluggers too. Just some suggestions. good luck.

48D

[Plymouthy Adams]

completely disassemble..does this mean you going to rebuild it or just remove the bolt on accessories covers and such. If you are going rebuild, home version..then hot tanking would get it done..however cam bearing and guides get a bit of eaten in the process..you can use red devil lye, please use all precaustion in working with this stuff...it cleans deep within the pores of the cast iron. Comes out looking like new..As it is cast iron, it is porous..and like a cooking skillet..numerous heat up and cool downs will impregnate the metal and will cause oil to eventually be under your paint again..that grease film is not because momma is not washing the skillet..it is coming from the inside out and coating the skillet.

[DutchEdwin]

Thanks for the advise,

Some guy's in my country advised me to used commen household oven cleaner. The brand we use over here should accoording to him even remove most of the factory paint from the engine.

I tried the wire brush on the air intake. Lots of work but you cannot get into the corners.

Diesel did some of the job, combined with the wire brush. This gives me thinking on the quality of the paint now on the engine.

I'll try the oven cleaner for removing the paint.

Normal green soap for degrease because this can be done by spraying on and remove with a high pressure cleaner.

BTW, at what temperature can POR15 be used to paint, It is now 10C = 50F overhere.

completely disassemble..does this mean you going to rebuild it or just remove the bolt on accessories covers and such.

Tim, a rebuild like....right now I have a bare block with only new freeze plugs and some oil plugs inside. The intermediate shaft bushing is still inside, is to be replaced in a couple of weeks when I order a new one from Hothemiheads.

New parts.....like reconditioned crank from a 241 dodge (the origional will only serve as a lamp post) new cam, cylinders, hydraulic tappets, water pump (advised by Norm to do so) well to make the list short, all moving parts are new except for the oil pump. So, a good rebuild

I know of the oil channels. The previous owner did a dumb rebuild. It did cost a crank. I've have my block cleaned and machined at a machine shop. When I checked in some channels I discovered that there was still a lot of dirt inside. I plan to do these after painting.

Procedure: I have the block in a engine stand. block the channel on one side, pore in diesel and use a stick of slight smaller dimension then the channel and go through the channel a few times. This will dissolve the slurry inside. Turn the block upside down and let it drip out. Do the proces again untill it is clean.

That should do the trick.

I already did the rockershaft. All channels were closed. Did take me a day to do it.

[DutchEdwin]

Look at the dirt inside my engine when I opened it.

This is what a clugged oil channel will do to your engine.

Crank bearing face misses 1mm, 0.04 inch of material,

on the cam, the left nose is good, the right nose should be of the same hight.

Total cost of repair......over $4000.

This high price, I have to pay 20% import tax plus high shipping costs .

It took me 4 years to find a good crack free crank.

[Norm's Coupe]

POR 15 is either an epoxy or urethane. Most of either are best used at minimum temperatures of 55 degrees or above. The colder it is, the longer it takes to set and cure. The warmer it is, the faster it sets and cures and also less working time.

I'm not familiar with POR 15 but the temperature range should be on the can. If not contact them for that information. Also, if the temperature is too cool it may even effect the curing so much that it will never properly set and cure. The minimum temperature they give will be for everything. Minimum Temperature of the item coated and air temperature should be maintained from the time it's applied until the time it's cured. If the temperature drops below the minimum during that period it will also affect the curing of the product. Being dry and curing are not the same. It could be dry to the touch, but it takes longer for it to cure.

[randroid]

Gents,

Ever anxious to point out the cloud inside every silver lining, may I caution against using WD-40 inside the engine. Don't get me wrong; I love the stuff but one of the reasons it works so well is that it's formulated to break-down petrolium products. I have used a synthetic silicone-based grease (Super Lube is what I have on hand) on a half dozen engines (VW, my 218, etc,) with no problems whatsoever. It also gives the bearings something to spin on during the initial starting of the engine, before the oil gets to them the first time.

When I painted my engine I did it in a body shop owned by a friend, and he had me wipe the whole thing down first with the solvent used to thin the paint, saying it gives everything a little more tooth. 10 years later the paint is still in fine shape, with the only problem being that I no longer want a Seafoam Green engine.

-Randy

[Plymouthy Adams]

clean and clean and clean..use gun cleaning bore brushes..wash with soap and water and soap and water..and then rise..cannot get them clean enough..the oven cleaner will work..sounds like it has been dipped already at the machine shop..you just need the surface and handling oils off it..blow it dry and spray it with a moisture displacment (WD-40) after assembly of larger components..you can clean and paint then.

if you are using your old pump..be sure to take it apart and clean it also..as long as it mic's to tolerance and not scored on the veins..put back. If scored..could result in lower oil pressure..

POR 15 web sites abound on theinternet..most info can be gleaned there..if not I have a brochure in the shop someplace...

[DutchEdwin]

Tim,

No gun brush here. In my country, if you own a gun, you get to go to jail. We can only argue with each other like the Neandertallers, the good old bat. Í'll have to use modified lab pipe brushes.

The engine is cleaned in a machine shop washing machine. But covered with a bit of oil to prevent it rusting.

Thanks for making me conveniant with water and soap.

POR-15 will dry due to a reaction with water in the air. That is why it should be good for engine paint and rust preventing paint There are no microscopic holes in the paint due to ebvaporation of the solvent. But there is no temperature indicator on the can, neighter on the Dutch POR-site. Ill look on the American site.

[Plymouthy Adams]

bummer man...I was just looking earlier as I flipped through my wallet that my concealed weapons permit is due for renewal this year. Guess it all goes back to walk softly and carry a big stick..

[55 Fargo]

POR 15 should be used in temps of 10c or 50 f and higher, this paint has a moisture cure properties. The higher the relative humidity, the faster the paint dries, do not sweat or accidently get moisture in the paint, it will not be so good after that. This paint if not used in it's entirety will lock the paint lid on so tight it won't come off, either use it all in one shot or pour it from one container to to the other without getting it on the rim, or put a sheet of plastic on before covering it with the lid, it may work. Visit the POR 15 website for more info, the paint is very tough, but there is also a Zero Rust, ( they have lots of colors) paint, much less expensive and just as good, and there is Eastwoods Rust encapsulator. The POR is expensive stuff, I use Tremclad (Canadas Rustoleum), it's a very tough rust paint, but a lot cheaper in price..The Rock

[Plymouthy Adams]

I looked in my brochure..no reference to any temperature for application..so I looked on a can..none there either...so as long as it is thin enough to spread..go for it...at least that is what I gather...just not right..I would think 55F would be lowest temp I would apply if spraying..a bit lower if brushing...but not much lower.

[DutchEdwin]

Thank you all for your help. I looked on the US-web POR15.com. After searching through a lot of files I finally did find the temp range, 10C-35C.

I do know all the problems of painting with POR 15, do not paint out of the can, do not drop any sweat on the still wet paint, do not paint in high humidity like mist and shut the can with a plastic sheet. But thank you for commenting on that. I only want to paint the engine once. So POR 15 was my expensive choice.

Oh, one thing still puzzles me, POR advises to paint in two thin layers.

Is this nessesary?

When to put on the second layer? immediately after the paint is no longer sticky (3-5 hours) or can it be done a few day's later.

What to put on the exhaust manifold is still a problem to solve. High temp paint will finally come off because the manifold is greasy in the porous material. I think of using oven paint. It's black and needs the heat of the oven to dry. So a long drive will cure the paint.

Any other suggestions?

[Norm's Coupe]

Edwin,

I would follow POR 15's advise and use two thin layers. As you know regular paint will create runs if applied too heavy. About the same thing happens when you apply high solids epoxy or urethane to a vertical surface. It may not form a small run like paint does but it will sag, causing bigger run type marks. The can should tell you how long to wait between coats.

Sorry, can't help on the manifold paint. Seems like everyone has a problem there after a few years. That's probably one of those things we'll just have to keep redoing.

[PatS....]

bummer man...I was just looking earlier as I flipped through my wallet that my concealed weapons permit is due for renewal this year. Guess it all goes back to walk softly and carry a big stick..

Same thing in Canada. Handguns are very hard to own and a concealed weapon permit wouldn't be in the hands of more than a handfull of the 35 million people here.

The crooks and druggies, well they sure have 'em. But not the average Joe.

They tried regulating and registering long guns. That didn't quite work. 2 Billion bucks later they are scrapping that boondogle.

I know of one ex undercover cop who, after 18 years in retirement still carries, but they are about the only ones.

[Merle Coggins]

Oh, one thing still puzzles me, POR advises to paint in two thin layers.

Is this nessesary?

When to put on the second layer? immediately after the paint is no longer sticky (3-5 hours) or can it be done a few day's later.

I found this on one of the documents on POR-15's site, and it's pretty much how I used it when I painted my frame and other parts.

Apply POR-15 in thin coats.

For Two Coat Application: Apply second coat when first coat is tacky

but almost dry. If first coat is fully cured, wet sand first coat with 600 grit

sandpaper until gloss is dulled. Next, apply the second coat of POR-15.

TOP-COAT APPLICATION OVER POR-15 PRIOR TO FINISH PAINT IF USING PRIMER:

After second coat of POR-15 has been applied, wait approximately 45

minutes to 1 hour until the POR-15 coating is tacky; then apply a light

dust coat of primer and let dry. Next, apply a full coat of primer and

follow normal top-coating procedures. If primer is lacquer-based, apply

dust coat only after POR-15 is dry to touch.

“Tacky” is `defined in our writings as dry to the touch but with a slight finger-drag remaining."

Hope this helps,

Merle

[DutchEdwin]

Two layer.... this means, one hole day of painting in the garage because I do a two layer.

POR is very shy one documentation given with the can of paint. Running through a mountain of documents on the www, while it can be so easy written in one A4.

Hopefully the temp will rise so I can start painting. Prediction is night 10C, day 13C on Sunday. That's 3 above the minimum of 10C. Should do 15C in my garage.

That's washing the block on Saturday and painting on Sunday.

Can you imagine me being enthusiastic about painting , normally I hate paint jobs

[BobT-47P15]

One word of free advice that I was given when buying a can of POR 15 hi temp engine paint.......after you use it the first time, and when putting the lid back on the can.....put in some wax paper, a plastic bag, or something similar between lid and can. The say that lid will stick so tight you can't get it open again.

[james curl]

The dealer I bought mine from told me to never open the can, instead punch two holes on opposite sides of the lid with an awl and pour what I needed into a clean container then put a number 10 or 12 sheetmetal screw into each hole. That way very little moisture can enter the paint to activate the curing process. Then when you need more just unscrew the screws and pour.

[DutchEdwin]

Bob, perhaps a little more of your free advice, did you put the high temp POR on the exhaust? If so was the exhaust new or already used how long did the paint hold on to it?

B.t.w. good idea of those screws, although I doubt that I put less moister in the can. The volume paint out of the can will have to be replaced with air. Thus moister will come in. It will prevent a solid frozen lid, or do this the second time you use it and seal the can with paint after first use, preventing moister coming in because of a poor closing lid after opening.

For I live in the metric part of the world, what is the size in mm or inch of a number 10 or 12 sheet metal screw?

[anthonyb]

I used POR-15 on my 41 some years back. I opened the can and used the plastic wrap under the lid to allow opening. Never had a problem with excessive moisture inside the can, even here in central Texas.

Another unusual tip to extend the useful life of the product...store it in the refrigerator. The can I stashed stayed usable for a couple of years that way. Of course, getting the wife person to understand the concept may be more trouble than it's worth.

[Merle Coggins]

I agree on the moisture getting in regardless. You have to let air in to displace the liquid as DutchEdwin stated. So if there's moisture in the air, it gets into the can. Also, how would you stir the paint? All paints should be stirred before use, and POR-15 says not to use a shaker because it can mix in air bubbles.

As for getting pint under the lid... You can get nice pour spouts from POR-15 for a few dollars. They work pretty slick and keep paint out of the lid grove. But I still put plastic under the cap before resealing it.

Merle

[DutchEdwin]

Thanks all for your comment. Now painting this weekend the temp of the block is still below 50F . I guess I have to wait a few weeks for the temp to rise. So back to scrubbing with the other engine parts like manifold and gearbox with diesel using an old tooth brush.

I'll try to use oven cleaner the remove old paint. Let you know how it worked out.

When things progress I'll post some pics for the looks.

Edwin.

[james curl]

Almost all oven cleaner is sodium hydroxide ( lye) so should remove the paint. Baking soda in boiling or very hot water does a good job of removing paint. I have removed paint on small objects with the baking soda and boiling water, beware it does foam a lot. In my youth we would fill a 55 gallon drum with lye and water and place over a gas burner to clean engine blocks and heads. It takes a lot of water to neutralize the lye after cleaning.