How do I treat this surface rust?

This rust is all over the body.  It all sands off but what do I spray over it?  Do I need to treat the body with something after I get the rust smoothed out.  Epoxy primer?

Try POR15 Metal Ready. Its a phosphoric acid wash that will eat that rust off. Then you need to epoxy prime it, high build prime it, sand it till your hands are numb, then paint.

You cannot blast with sand or anything like it or car is junk. I use molasses tank to remove the rust but you have to treat with phosphate immediately or it will rust. If you get feed grade molasses and mix 9 to one with water it will remove the rust. I have a 275 gallon bulk chemical tank that I use to remove the rust. It does work an very great. I have panels in garage that have been bare metal for 6 months with no rust. I treated with phosphate right after molasses.







lucy poems summary

+1 on David's molasses solution, I just did some con rods and heads that were quite rusted and came up a treat

For a simple de-oxidiser use a vinegar spray diluted 50/50 and keep wet for several minutes, better to work it in with a Scotchbrite, rinse well, dry and get some epoxy primer or phospate onto it ASAP.

I had similar rust issues with my 71 when I bought it. I mechanically removed as much rust as possible with a DA, then used SEM's Rust Mort to kill the rust that was remaining. Fifteen years on, nothing has resurfaced.

Try POR15 Metal Ready.  Its a phosphoric acid wash that will eat that rust off.  Then you need to epoxy prime it, high build prime it, sand it till your hands are numb, then paint.

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For this stuff what do I do spray it on with a bottle, let it sit then hose it off?

For the molasses: 

isnt it thick sticky and messy?  

Where do you get it?

Where do you get the phosphate?

Is the phosphate liquid?

Mix it and spray it on with a bottle?

does the poor 15 and\or molasses remove the "rough to the touch" surface rust or do I still need to mechanically sand it first and then apply to remove any surface rust left behind that isn't "rough to the touch"?

Heavy rust like that you need to get off as much as possible before applying the acid. You also have to keep it wet for it to continue working. I found that the thin plastic drop cloths worked great for this. Spray the panel down well and lay a piece of the plastic over it. The plastic keeps it from evaporating and the thin material conforms to the panel nicely.

David's molasses solution is a great idea, but not everyone has a place to store a large plastic container like that.

https://www.por15.com/POR-15-Metal-Prep

https://www.semproducts.com/product/rust-morttm/morttm

I totally agree with Hemikiller.

The way I used it was......  

I sprayed it on straight, used 400 wet/dry sand paper and lightly wet sanded it with the acid.  Then I wiped it off, and started again.

If that isn't doing much, spray it on, cover with plastic, check it every 10-15 mins by removing the plastic, wet sanding, then wipe it off.  Repeat till you have clean metal.

You shouldn't have to use anything more coarse than the 400 with this product.  It works amazingly well.  

When I did my engine block, I barely had to do anything, spray it on, wait 10 mins rinse it off a couple of times and it was shiny metal.  

You just don't want to leave it on too too long.  It is acid after all and you don't want it to cause any pitting you will have to fill.  Just start in a small area and use your best judgement.  It really is an amazing product.

This is another good product too.  Its called Eastwood After Blast.  Its similar to Metal Prep.  It also has Zinc, so it leaves a Zinc Phosphate coating on the surface to prevent flash rusting.  I have seen people use this and store a bare metal panel in a controlled environment for over a year with no flash rust.

https://www.eastwood.com/ew-after-blast.html

If you feel you want to mechanically remove as much as possible first, this is an excellent tool from eastwood.

https://garage.eastwood.com/eastwood-video/watch-the-contour-sct-remove-surface-rust-and-condition-the-metal-on-a-corvair/ 

Still your best bet is to coat any body panels you clean with epoxy primer.

You can do the painting at home no problem, you just need the proper equipment.  The biggest issue is getting the air dry enough.  This time of year is the best time to paint.  The air is fairly dry and you will just need a decent desiccant dryer and trap.

If you just want to seal the panel to prevent further rusting and don't intend to start body work any time soon, you can use the eastwood 2k rattle can epoxy primer.

https://www.eastwood.com/ew-2k-aerosol-epoxy-primer-gray-26898.html

I will say this. The molasses method works extremely well and is cheap. I buy the jugs of feed grade molasses at the local tractor supply store for around $8/gallon. The downfall is as stated,

1. you have a large container full of molasses.

2. it can start to smell pretty ripe after a while, especially if it is warm out.

3. it is kind of messy but not too bad.

4. if outside and you have wildlife they will be attracted to it. Bears, coons, etc.

on the plus side it is 100% environmentally friendly.

Wade,

I get the molasses at our local feed and see store. It is from $18.00 to $20.00 for 5 gallons of liquid molasses. Do not get the dried will never dissolve in water. You mix 9 parts water with the molasses so you get 50 gallons out of 5.

If you want to bring a fender up and put in the tank and try it you can. It is slow as molasses and takes week or two to do it's job but no effort. With the molasses thinned down it is not sticky and I just hose off and put the phosphate on I have had parts in the shop for months after cleaning and no rust coming back. The phosphate is the key.

You will probably be better off using the phosphate with shrink wrap or saran wrap to prevent evaporation. Good wire brush on drill or side grinder with wire brush.

Even is you were to blast a heavy piece of metal you still need to sand it. Sanding gives a much better surface to adhere to than blasting. NEVER blast sheet metal. If you want to know why take a flat piece and blast it and watch it curl up. Just recently my friend that does restorations had a guy show up with a Datsun 240 Z and wanted him to restore. They talked some and the owner asked about blasting it. Clay told him only plastic media and it would only remove the paint not the rust. So the guy leaves and in a couple weeks shows up with the body on a trailer and he had taken to a sand blaster and had it blasted. The whole body was ruined. It looked like you stood and beat it with a hammer for days. The idiot that blasted it should be shot. The car was scrap or just chassis parts.

Rust shows up in these cars after years and does not give up easily.

The convertible I have that was dip stripped has not shown any signs of bleeding from the joints as many have said it would. Has been at least 6 years sitting in primer and sat outside some with no rust or bleed. When they dip it does take all the rust, paint, undercoating, sealer and is bare metal. They need to have a hot phosphate tank to dip in after the strip or it flash rusts in minutes.

Wish I had the space to have a massive pool of molasse for big body parts...

Treating the rust where you can access it, is with the above said solutions is done relatively easy. Done tons of small hardwares, parts. They all regained their ancient glory.

But when you want the rust out of the inside of the hood, deck lid, doors, upper part of roof/quarters... that's an entire other story.

Unfortunately, you need put lots of efforts into the removal in these areas, if you do not really remove/stop the rust, after 50 years the metal is really thin in some places and its not gonna take long before holes start to emerge.

Hello,

This is the stuff to use. It has sulfuric acid in that eats the rust! Wear gloves !

http://www.ospho.com/index.htm

Thanks guys! So if I am reading these posts correct I should follow the below process. Am I correct?

1. I should remove as much as I can mechanically

2. The preferred chemical is molasses mixed with water 9:1

3. brush the molasses on and let it sit. Then hose it off

The hood will have to be replaced as it has rust inside of it and its already started to eat away the metal from the inside out. I wanted to get another hood with the hood lock holes already in it anyway. The doors and the trunk lid are solid from what I can tell.

molasses works when dipped and soaked for an extended period of time. it will not work sprayed on and hosed off. IE if you are doing a fender you need a huge tub of the mixture. put the fender in it fully submerged. Check back in 2 weeks.

You will need to submerge the part in molasses for about 2 weeks.  I don't think brushing it on will do the same thing.  Its a VERY slow process like David said.  It works good though.  

Use the other products and saran wrap for a brush on solution.

Ive never used OSPHO but it looks like some good stuff.  Just be VERY careful with it.  It contains "Dichromate".  Most Dichromate compounds are Hexavalent and EXTREMELY Carcinogenic, and are also a Marine Pollutant, so disposal is an issue with that product.

"SKYCO OSPHO: a balanced formula of Phosphoric, Dichromate, Wetting Agents and Extenders . ."

You will need to submerge the part in molasses for about 2 weeks.  I don't think brushing it on will do the same thing.  Its a VERY slow process like David said.  It works good though.  

Use the other products and saran wrap for a brush on solution.

Ive never used OSPHO but it looks like some good stuff.  Just be VERY careful with it.  It contains "Dichromate".  Most Dichromate compounds are Hexavalent and EXTREMELY Carcinogenic, and are also a Marine Pollutant, so disposal is an issue with that product.

"SKYCO OSPHO: a balanced formula of Phosphoric, Dichromate, Wetting Agents and Extenders . ."

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WOW, and OSPHO is legal to sell?!

If you feel you want to mechanically remove as much as possible first, this is an excellent tool from eastwood.

https://garage.eastwood.com/eastwood-video/watch-the-contour-sct-remove-surface-rust-and-condition-the-metal-on-a-corvair/ 

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This is a cool machine.  I am seriously considering buying it.

Like everyone has said the molasses is a dip in a tank thing. I have the 275 gallon bulk chemical tank and it is not deep enough to do complete fender. I have looked for something deeper but gets expensive for a hobby. Yes you could use a kids swimming pool but things like hoods and trunks with the inner reinforcements need to be hung vertical to get the air pockets out. You can weld plastic and make a deep narrow container but I do not have one of those.

You can see on the trunk like where the molasses stopped. I have since fill the tank all the way to top. When I take the parts out I use razor blade and scrape off lots of the loose paint then use aircraft stripper to get more and then DA sand and use the phosphate to get down in the rust pits. That trunk lid has been sitting in garage since last Oct. when I did it with no primer on it and it has not rusted. We have had record rains probably over 50" this year so not a dry air place. I do not have heat or air in the main part of the garage. The phosphate does it's job stopping the rust.

Here is probably the best way get the rust off but there again the cost is not cheap. Laser there are several I know nothing about who makes the best.

https://www.roadandtrack.com/car-culture/classic-cars/videos/a30597/best-rust-remover-laser/