painting engine block

[Barry K.]

hi all

I pulled the intake, exhaust manifolds, and valve covers off my '65 L76 motor. While those pieces are off to get cleaned up I figured it was a good time to touch up some areas on the block where paint has chipped off or been eaten off by various fluids, etc.
I originally tried painting the areas with a small paintbrush but without much luck. I went yesterday and picked up some small foam brushes hoping it would lay the paint down better than the other paint brushes I had and tried but it's not working much better at all. The closest I can describe what's happening is than when I try to brush the paint on it's like it's sitting on the surface but not laying down properly almost like water sitting on a surface that was covered with oil first (the basic oil and water don't mix and the water will bead up).
The paint just wants to almost bead up like and instead of laying down even and flat it want to run and leave brush marks and tiny areas almost like pinpoints don't want to accept the paint at all.
I prepped &cleaned the area best I could with what I had on hand and thought it would be ok but obviously it's not and I need to just sand off what I've done and start over. I had prepped it by first scrapping off all rements of the old gaskets and any loose paint, than wiping it down with a rag soaked in brake cleaner solvent, than wiping it down again with a rag damp with clean water and let it dry thoroughly. So far the only area i've been working on trying to get touched up is the flat part of the heads where the intake mates up to it. I haven't even tried to work on any other part of the motor yet with the paint.
Go figure, I was expecting the paint touch-up on the block to be the easiest part of this project and it's rapidly turning into the biggest PIA part of it.
BTW, I reason I'm trying to paint it on with brushes rather than spraying is to avoid overspray everywhere including my new paintjob on the body and all over the rest of the engine compartment.

any suggestions on the best way to paint the block and to properly prep it first so the paint lays down correct and adheres?

[Mark B.]

Re: painting engine block

Barry, you are a glutton for punishment! Just kidding. Your problem sounds like the surface is not free of oils and dirt that is keeping the paint from adhering properly. First, get some Brake Cleaner (I prefer 3M bought at NAPA) and coat a rag that you can use to clean the area to be painted. Then, use a paint scouring pad that can be had at Wal-Mart to surface scratch the existing paint surface or metal to allow the new paint to grab and hold. After etching with the pad, use the brake cleaner to clean the area well before painting. Use several light coats of paint for a good wear surface and coverage.

If you ever pull the engine and decide to paint it with spray paints, use many light coats (about 4 to 5) before giving the block a final wet coat. This keeps the paint from chipping and peeling as the light and thin coats provide bite for the top coats that get progressively heavier. ood luck.

[Barry K.]

Re: painting engine block

Mark
funny thing is that I DID use brake cleaner to clean off the surface but I guess it just wasn't a good enough job. I'll have to sand off the paint that I already put on there and start over again. I didn't use a scouring pad so I'll try that also.

thanks!

[Donald M.]

Re: painting engine block

Barry, Use a scouring pad soaked with lacquer thinner. Be careful,wear rubber gloves and use in a well ventilated area. Also, cover up the rest of the engine compartment and fenders, cowl ,etc. There's almost nothing that LT can't remove!

[Joe L.]

Re: painting engine block

Barry-----

Yes, I can virtually guarantee you that you didn't get the block clean enough and that's the cause of your paint adhesion problem.

Keep these words in mind: "The difference between failure and sucess is very often the difference between doing a thing nearly right and doing it exactly right".

[Barry K.]

Re: painting engine block

Joe, I'm in 100% agreement with you, and I do want to do this job correctly. Obviously I didn't do a good enough job cleaning it the first time around so it's back to square one.
I'll use lacquer thinner to remove the new paint I put one, reclean it all over again and try over.
Perhaps I'll take both advices given and clean it with BOTH brake cleaner and lacquer thinner plus hit it with the scouring pad before trying to paint the required areas again.

Off to the store first thing in the morning for supplies.........

[Joe L.]

Re: painting engine block

Barry------

You can have it not clean enough, but you can't have it too clean!

[Barry K.]

Re: painting engine block

I hear ya Joe
i'll make sure she is real clean this time!

[Philip C.]

Re: painting engine block

Barry dont use anything but wax and grease remover any body shop supply carries it.(dont use 901 for this, they might suggest it) I assume the block was spray painted now your touching it up, but with what? Use the same spray paint but spray it heavy in to the paint can top or on a piece of my favorite aluminum foil and use a small hobby brush and touch it up. That foil is the best for masking off stuff it raps and moulds around everything! It does not have to be real clean doing it this way, if your spray painting it does, good luck Phil 8063

[Barry K.]

Re: painting engine block

Phil
hate to disagree when I'm the one asking for help and advice, but i've already learned the hard way that it DOES have to be real clean even by touching it up with a brush which is how I tried it already.
Seems I must not have cleaned the area well enough as there must have still been a thin layer of oily residue, perhaps it was from the brake cleaner itself, that kept the paint from laying down correctly.
I like the idea of foil to wrap things - it would be easy to work with and as you say it will mold around everything.

I just got back fro ma visit to my painter who just did all my bodywork and new paint job and while there I explained my problem on this engine block touch-up. He suggested acetone to clean everything off as it won't leave any kind of residue and he will give me a bunch of the plastic he uses to cover cars in his shop plus about a half roll of the paper he uses to mask off cars.
I'll use the acetone to clean everything, than drape the car in plastic to protect it from any overspray and use the paper to mask off everything in the engine compartment except the block. I can use your foil idea to cover the open valve train in the heads. with everything cleaned and completely masked off and covered than I should be able to safely spray the block for a better result......... I hope!