I have spent 4 days trying to get the rust off the hood of my 1959 F100. It didn't look any worse than other old trucks I have looked at - but 4 days later I am ready to give up and admit that I have not really improved it. It still has deep rust pits and I fear it will not hold paint.

I used lots of naval jelly as per instructions - repeat coats with each one getting heavier and staying on longer. I gave up on the easy chemical cures and started sanding - 180 grit on the DA to start, then 80 grit on the inline, and now 36 grit on the grinder.

Grinder works as things are smoother, and I have to be careful around the few areas of bare metal not to remove too much, but there is a hard black coating that resists everything I throw at it. And I still have the rust pits.

1. Is it possible the black coating is some sort of rust converter a previous owner put on? What is this substance? It seems harder than diamonds.

2. Will sandblasting remove it? I found a local place that will sandblast the hood for around $100 - is that a fair price and will it work?

3. I want the hood to look very good as that is what I have to look at everyday, but the cab roof and bed rails are in about the same shape. Any ideas short of sandblasting for those?

Thanks for your ideas -

Clint

 

Save your self the work, get it blasted. Make sure the guy isn't just sand-blasting it, your asking for warpage, but rather media-blasting it with less harsh materials. The black coating may just be a converter, they usually turn black and penitrate the metal. Have you tried a wire brush on a grinder or drill(make sure you use one with thin wires as they won't scratch the metal)? -4speed

 

OOPS, forgot to mention 4" cup wire brush on the 4" grinder - wore one out, and about half of the new one. Was the first thing I did, even before naval jelly. And no worry about scratching the metal - never got down to it!

Bottom side did clean up enough so I would have painted it and not worried about the paint falling off or bubleling due to rust.


Sandblasting causes warp?

 

Take off all the loose surface rust with a course 3M Nylon surface prep disk, then use a rust converter (NOT a sealer like POR etc.) on the pitted areas according to the instructions. After that dries spray the hood with an epoxy primer. If the surface is not smooth, shoot a coat or two of a high build primer and block sand it smooth being careful not to sand thru the epoxy (different color primers make it easy to see how deep you're sanding) Finish with a coat of primer/sealer per manufacturers instructions and your color paint. Ask your paint supplier for help with selecting exactly the right products to use.

 

Sandblasting does warp metal, you'd probably be okay with a hood since it has reinforcement all over, but areas like doorskins and roofs with very little support behind a large area tend to warp with sandblasting because of the heat and pressure caused by the sand. Media is the way to go. -4speed

 

I like Ax's idea. I think he is referring to the same disk that I have often used to remove paint and rust. They come in different colors depending on how hard they are. (Mine is purple and hard) I believe that they are made of a nylon mesh with some sort of carbide coating applyed. They are about 1/2" thick/6" wide and last for quite a bit of surface prep. I bought the Makita sander to hold the disk. I think it was about $50 at Home Depot. It turns at a very high rpm so the paint/rust don't have a chance. I would say you could do the whole hood in an hour. So, I vote to by the high-spead sander and the disk instead of giving the money to the sandblaster. That way you will be all set up when you get to the fenders, running boards, cab, etc., etc. Good luck, Jag

 

I'm a fan of sand or media blasting (more specific, having someone else blast it for me), but if you have a lot of pits and your blaster isn't too careful, you can end up with a lot of holes in your metal. Most of my stuff i had blasted came back just fine, but my tranny cover was swiss cheese. I've put a couple of layers of fiberglass cloth on it and it's fine, but with a hood (that is the main piece of sheet metal you see while driving), you want to be careful with it to keep it looking nice.

Scott

 

For actual paint removal I use my 4" Makita angle grinder with what is called a flap disc. The flap disk looks like sheets of sandpaper arranged like a fan in a circle much like you might fan a deck of cards in a circle on a backing. They come in different grits, 80 grit being about ideal for taking off multicoats of old paint. They are a little pricy @ ~6.00 each at local suppliers, but I buy them from an ebay supplier at ~ 1/2 that price in pkgs of 10, and they'll mix grits in the pkg. They last much better than any other abrasive I've tried and run cooler due to the fan like construction blowing air while sanding. I then go over any rusty areas or clean metal I'm not going to use any filler on with the 3M surface prep disc (also comes in sheets for use on a sanding block or by hand).
That gives just the right tooth for primer or putty. I use Rustoleum rust converter from my local DIY store. Don't waste money by coating clean metal with the converter just use it where there was any surface rust or pitting, it only reacts with rust. Don't fail to use the converter on the back side of any panels as well. Sand or glass bead blasting can warp and pit as well as hardening the surface of the metal making straightening or smoothing more difficult. Plastic media, walnut shell or soda blasting is the only panel blasting you should even consider nd only done by someone experienced in blasting old vehicles (ask the local custom shops who they use). Plan on doing a lot of cleanup after blasting to get all the residue out of all the nooks and crannys. If you do choose blasting MAKE SURE you don't touch the surface with bare hands or get any moisture on it and paint it the same day or else give it a wash with a rust preventive product but still paint it within a couple days, any longer and you'll need to start over.

 

I am not a fan of sanblasting hoods unless it is reinforced and/or highly crowned. For example at edges and hinge support areas are OK. Do not let anyone loose on the flatter sections of the hood and avoid the high pressure (>80 psi). Otherwise you will warp the panel. For these reasons, I do my own sandblasting.

 

The fenders on the back of my truck were in extremely bad shape with deep rust pits covering about 50% of the fenders, but I couldn't find a better pair. For a temperary fix, until I could find another set, I sanded them with 36 grit paper on a DA and then coated them with Extend rust converter. I then did the remaining rust and dent repair. I then applied epoxy primer, surface primer and then blocked them out. That has be over seven years and there is not visible sign of the rust coming through.

Just my 2 cents

 

I would possibly look for another hood in better condition, Might be cheaper than a media blast, sandpaper, your time......

Oh..I have a 59 hood already in primer....

Just seems like it would be easier to find a better hood to start with
less agrivation and a time saver

Glack

 

Hoods are expensive to ship.

 

I go thru Medford 4 or 5 times a year - have family in Grant's Pass. Actually will be there next week.

That being said - I will keep trying on my hood. I got to learn before I tackle the cab top or bed rails.

 

From personal experience I can tell you my system will work with minimal effort/expense and will last most likely as long as you own the truck.

 

AXracer - found flip disk sanders on EBay, but this can't be the guy you were talking about - http://stores.ebay.com/STIMPSON-SALE...erLinksQQtZkm?

he only sells one at a time, and does not even give disk diameter in his ad. Which one you use?