Replacement gas tank. Should I wire-wheel the rust or put primer over it?
 

Alright, I bought a replacement, albeit used, gas tank for my 7. I cleaned it up real nicely and now you can run your hand over it and not get any dirt on you. However, the top side of the tank, minus the center area that's usually covered by the foam padding, is pretty much topped with rust. Should I wire-wheel the rust off before putting primer on it or can I just put primer over the rust? That's a lot of area of rust to deal with and I won't touch it unless I have to. I also plan on getting that POR-15 stuff once I get enough money to actually buy it.

Putting paint on top of rust does nothing for you. Wirewheeling the rust won't do much either since its probalby more than surface rust (that is its eating into the metal, pitting it with rust spots) I assume you don't have a sandblaster (the only "permanent" solution) so wirewheeling the area and putting por15 on top it will be good for quite a while. As I said wirewheeling isn't great, but its better than nothing, and por15 seems to last quite a while.

I'd get a new gas tank but no one offers one. Not even Black Dragon Auto. So, I'm stuck with just getting another used one from a guy who parts out FBs/SAs.

i have had several that i wire wheeled the rust off or blasted off at the car was and they end up with little holes all over them.
the best idea would probably be to install it as is.

http://www.mazdatrix.com/c-pump.htm

Just FYI as long as you dont have an SA, mazdatrix will have a tank for you.

I'm about to do this and have done the research and bought the parts.

Inside of tank
Run tank nearly empty or use filter to pump it dry.
Drop tank. Drain tank and allow to dry.
Put chain in tank to shake around for awhile to dislodge anything loose. Remove chain. Pour in acetone as a rinse. Pour in more acetone til it comes out clean. Let dry completely. Get a quart of Red-Kote from Carquest. Use it to coat the inside of your tank.

Outside of tank
Remove sending unit and filler neck. Replace both.
Get your tank straps off and get them powdercoated.
Get most of the rust off the outside of your tank by any means.
Paint the outside of your tank with red or black oxide primer. It WILL paint over light rust.
Finish paint the outside of the tank with the spray truck bedliner that comes in rattle cans.

[U]

I thought POR-15 meant "paint over rust". Isn't it supposed to turn rust back into a metal oxide or something?

- David

Excellent, thanks. However, that's a very steep price for a gas tank. And, I'm sure a dealer (if it isn't discontinued) would also charge the same. Maybe when I start making more money, then I'll look into getting a new one like that.

Interesting that they list the same part number for the 84-85 12a and 13b tanks. the 13b one has much better and bigger pick ups. I wonder if all of them were the same and I can brodden my search for a tank to include 84-85 12a tanks...

My guess is that they dropped the 12A tank from inventory/production. The only difference between the 2 is the sump cup for the SE. The fuel pickups are different and usually not part of the tank.

85 FB, wait until you can afford the POR-15 to do your tank. Do not coat it with anything until you have the POR-15 on it 1st. In the mean time, you should remove any loose rust scale and all of the oem coating. The POR-15 will not adhere to the bitumen based undercoating from the factory. Paint thinner or mineral spirits will help soften the oem undercoating so it can be scraped off. Once most of that is removed, a scotchbrite pad and thinner wil take care of the rest of it. Make sure any remaining film left over is removed, then wipe the tank down with a wax and grease remover or Prep-Sol. Prep-Sol can be found at WalMart or your local auto parts store.

Once you have the tank coated with the POR-15, you can use an epoxy primer, or coat it with the truckbed liner. You will need to scuff the base coat for good adhesion of the liner.

I have the same dilema, I think i'm going to put a fuel cell where the spare tire well is. I personally am going to be running a high hp setup, and I don't want to overlook something like the fuel tank.

Why go through all that extra work Dan? If you need an oem tank setup for your turbo, I can do that for you.

You have me interested now :). What im looking for is a tank with a -10an feed bung on it, and a -8an return bung and baffled of course. I must admit it would be nice to have an alternative for all the fabrication that would be involved in properly mounting and securing a fuel cell...

Steve84GS modded his tank to accept the 2nd gen intank fuel pump and has posted a couple of pics of it. I have done one tank, but have not posted about it because I'm not happy with the way I installed the ring and flange to hold the FI pump. I have not worked with AN fittings, but I suppose they could be added to the mix.

If this is the way you want to go, I can mod a tank for you and bring it with me when I deliver the shell to Sam in Canada later this month. That would eliminate the cross border fees and such and could be mailed to you from Ontario.

PM me later and we can discuss fittings and pricing.

Wow, that's a lot of work for a gas tank and prepping it up. Yes, it is worthwhile to do all of that for the long run but I don't live in an area where I can freely, and easily, do all of that. It is starting to become freezing cold outside and I can't be doing it in the room that I'm in. Call me lazy but not all of us have the advantage of having their own house with a nice garage to do their work in. And, it's really cold outside and I don't want to do it in the cold.

Hell, you're in Virginia, want cold, come to my house, lol. Yes, refurbishing a tank can get quite involved but done right, you should not have to worry about it again, ever. It takes me at least 2 full days to strip one down and renew the outside of one. If you don't have the facilities to do it yourself, and can afford around 2 weeks down time, PM me. I can take care of it for you in my nice, well equipped and heated shop.

Your other option is to find a radiator shop the refurbishes fuel tanks. First thing you need to determine is if the tank is in good enough shape to warrant the renewal. Otherwise you start looking for a good used tank ot bite the bullet and buy a new one for approximately 437 bucks, plus shipping.

Wish I could afford 2 weeks of downtime but I don't have a backup vehicle to allow that. When I asked the guy for a gas tank, he said this was the best one of his small lot of tanks. If push came to shove, yes, I can work on the tank. Just really seems like a major time consuming hassle. Except for the cleaning, which I did outside, I do most of the stuff in my room (I rent right now) so that means trying to work in a confined space.

I do understand the fact of not having to deal with it ever again, but I am curious about this, maybe you can shed some light on the subject for me. The bed liner stuff (I've only seen the roll on stuff), do I really need that? That's only for protecting it against knicks and scratches, right? I'm sure POR-15 and primer and paint can take care of rust and the elements, correct?

There are other rust converters on the market, you can buy a small container for $5-$15.
I've used "Xtend, or Extend", and "Conquest", both worked fine.

edit:
I think the primer or top coat on the por-15 is for uv protection, other converters need this too.

Good post! I will be hitting this road when I get home next week so this is good info. My gsl-se tank:
http://i102.photobucket.com/albums/m...B/PC030002.jpg

You just need to look outside the box. Place a WTB ad for you tank requesting someone from California, Arizona, or anyother dry climate area. Shipping is not much thru DHL because the tanks don't weigh much.:)

Wow, thanks, man. I never thought of that, that makes a lot of sense. :)

KimFB, thankfully the tank I have doesn't have that much surface rust on it like yours. ;) Tho, that's not counting what may be currently on my car.

Applying the bedliner, or even the oem style undercoating, protects the coating underneath it that protects the tank. Our tanks are galvanized from the factory, but every tank I have redone has had rust spots that started where a rock has chipped the undercoating, allowing moisture and rust to start doing it's thing.

I recommend the truck bed liner because it has a higher impact and chip resistance than the bitumen based undercoatings. Less chance of those nasty little pits getting started and creating pinholes in the tank.

I've got a tank from an 82 that I'm trying to sell. Contrary to what rx7doctor mentions, it's kinda pricey to ship because of it's size so I'm not asking for anything more than the cost of the box and shipping.

http://i2.photobucket.com/albums/y37...k/HPIM0150.jpg
http://i2.photobucket.com/albums/y37...k/HPIM0148.jpg
http://i2.photobucket.com/albums/y37...k/HPIM0146.jpg
http://i2.photobucket.com/albums/y37...k/HPIM0145.jpg
http://i2.photobucket.com/albums/y37...tank/tank4.jpg
http://i2.photobucket.com/albums/y37...tank/tank3.jpg
http://i2.photobucket.com/albums/y37...tank/tank2.jpg
http://i2.photobucket.com/albums/y37...tank/tank1.jpg

^ Aparrently you have not tried DHL, I believe it only costed like $25.00 to ship it from California to the Midwest the last time I did one. Also don't rule out the USPS for big items also. Theres also greyhound. Remember to look outside the box,lol.

I used DHL to get the FC tank I'm tearing apart (for the in tank setup for my t2 swap) and it cost like $45 to ship to me. Granted it had the whole fuel pump assembly with it, so that added some weight. The guy I bought it from stuck the whole thing in a garbage bag and put a label on it, haha what a way to ship something...
Oh and as per the original question, if you don't have the ability to do it the "right" way then simply cleaning off the loose rust and slapping some por15 on there will prolong its life enough to keep you happy. The smallest por 15 can is like $8 and you won't need more than two of those to coat the whole outside, probalby not even that much, so its affordable enough.