Gas Tank Restore 101

Stackett · 08-05-2005, 06:29 AM

For the past two years I have been reading, learning, purchasing, and drueling over what goes on this BBS. Now it's my turn to contribute something that only a few have done.

I asked the question a couple of weeks ago if anybody besides Fishcop had redone/restored their gas tank. With no replies, I started last night. With the advise from Fishcop here is what I have done so far.

I purchased the new addition almost 4 weeks ago with the fuel system being almost totally disassembled. I started working my way through to see where the problems were and found that my gas tank was filled not only with gas, but had about a gallon of water, a 16 ounce cup of rust, and another 16 ounce cup of sludge. The other 10% was actual gas.

Realizing that I had to do something about the gas tank, I quickly did a search and found very few results. Like I said earlier, Fishcop was about the only one that had gone through the same ordeal.

Once I got the gas tank out, I noticed that it didn't have the same textured feel that my 80 SC had and believe that the tank has been repainted at one time or another.

I am posting some photos of what I have done and how I am proceding with caution in the project.

Please feel free to add to or help me in any way you might think I can improve on what I am doing. Did I see where Wayne had asked for some more indepth projects for a new book? Maybe this is one of them.

I started with stripping the entire outside and finding some way of closing up all 5 yes count them 5 holes/tubes. In the instructions of POR15 (The Gas Tank Restore Kit suggested by Fishcop) they say to leave the chemicals in and set on each side of the gas tank for 2 hours. Later, after talking to a POR15 rep, he told me that it should only take about 30 minutes to an hour per side.

So I had to find a way to close up all the holes so the chemicals will work. I didn't want to use a cork or rubber stop, because I wanted to clean all the way to the end of each tube.

So I went to the local plumbing store and purchased a couple of brass caps and one rubber extension with a cap for the main inlet.

I had made a rubber gasket for the hole where the fuel sending unit goes, but it doesn't look like it will hold so I'm having a metal plate made to go over the gasket.

I'll add that tonight and start the cleaning/stripping process tomorrow morning. I will post updates on the process I'm going through and show my final results. I don't plan on restoring the entire compartment just the gas tank. I think Fishcop has done an excellent job at doing that.

dweymer · dweymer's Garage

Nice work, the POR stuff works well. What are you going to use on the outside? I just painted mine matte black for simplicity. Do not get it on your skin.

Stackett · 08-05-2005, 06:50 AM

I've contacted Fishcop to see what he used on the outside. I want that textured look. I've purchase some silver high heat paint for it, but haven't gotten there yet.

dweymer · dweymer's Garage

I am pretty sure John(fishcop) mixed grey and black stoneguard for his. It is available in spray cans, and I like the look better than my matte black.

Stackett · 08-09-2005, 04:42 AM

For those of you that have never used POR-15, it has about 5 steps in it and has to be done to the letter. I completed the first step and it didn't get all the stuff out like I thought it would, but there were some things I didn't think would hender my progress.

The first step is called Marine Clean. You take 1 Quart of their Marine Clean and 1 Quart hot water and pour it into your gas take. Close it up and shake it around. You let it set for about 30 minutes per side to clean every inch of the inside.

Well the problem was because of the shape of the 911 gas tank, 2 quarts of solution cannot get every inch unless you set it in different positions other than the normal four sides. Also there is a baffle system inside the tank and I think it is clogged up.

To get to the bottom of the baffle system, you need a very large hex wrench/socket to take the plug out of the bottom. Hopefully I can find a wrench today to open the plug.

It did clean out a bunch of rust/sludge/crap, but there is still some stuff in the bottom and around some of the side walls that I want to get out before I got to the next step. Note the second step is just a repeat of the first step.

When I get the hex wrench, I'm going to take it to a car wash and use a pressure washer to try and clean out as much as possible before I use the second quart of Marine Clean.

Again, I want to be positive that I have every thing out and it's as clean as possible before I go to the next step.

I'll keep you posted.

JK-81SC · 08-09-2005, 08:17 AM

Scott,

You don't need to buy a hex wrench, if you own a Craftsman 13/16 spark plug socket (other brands may work as well). I read this tip from an earlier post, and it worked perfectly when I did my tank a few weeks ago. Take an extension and put it into the socket where the plug would normally fit. The hex on the end of the socket fits perfectly into the gas tank plug. See photo below.

Stackett · 08-09-2005, 10:18 AM

Jeff,

I guess I should have posted all that stuff on Saturday when I ran into my speed bump. It worked perfectly. I went home during lunch and snap, it worked. I loaded up the tank in my truck and plan on hitting the car wash this afternoon.

Thanks to Jeff and everybody else that participates on this BBS.

Fishcop · Fishcop's Garage

Great job Scott!

As mentioned earlier, I used an Acrylic (water based) Stoneguard in black and white - you can use the solvent based one, but it's harder to clean up. I poured small amounts of the black into the white to get the grey I wanted. You'll need a "schutz" gun (pretty cheap at $30) and set pressure to about 60psi. Remember to prime the metal first with an appropriate primer/undercoat.

Stackett · 09-15-2005, 10:47 AM

It's been over a month since I've been able to do any updates. But I will be working on my tank this weekend and hope to have everything finished. If you have decided to follow in my footsteps, I just have one bit of advice before you start.

My tank was a basket case. Even though it didn't have any holes, it still needed a lot of work.

If your's is in as bad of shape as mine was, or you at least think it is in bad shape, you need to purchase an extra quart of the Marine Clean and Metal Ready.

The inside of the normal Porsche Gas Tank has a lot of baffles and one quart will not do the job. Thanks to a fellow Pelicanite who had some leftover from another project, I'm going to redo the process to get every little bit of crap out of my tank. I hope to have photos from a borescope machine to show everybody how it works.

Stay tuned for more updates.

Rich76_911s · Rich76_911s's Garage

Thanks for the write up it is certain to help a lot of people. Here is the link to the kit for anyone that is interested in the future.

http://www.por15.com/product.asp?productid=316