VCCA Home Forums GENERAL DISCUSSION General Discussions Sealer for gas tanks

I just picked up a '28 National and I'm currently working on getting gas flow to the engine. Line from the tank to the vacuum is clear, along with the others.. The issue I have is the person before me etched and added tank liner to the vacuum tank and it is all gunked up.
I have tried soaking a chunk that I broke off in paint thiner, but it's not breaking down at all after 24 hours.. Only thing I can do is try and peal it away with a long screwdriver. But I'm still trying to get it out of the drop where the gas flows to the carb ( on/off flow screw)

Any suggestions?

You might try MEK (MethylEthylKetone). It is the strongest solvent generally available.

Thanks, I'll try try and see if we have nearby.

A suggestion from experience!! If you do ever set up the tank to operate on the vehicle, buy some plastic in-line gas filters to mount one just before the carb. I also had a tank lined and was constantly changing filters that were picking up pieces of the lining as it broke down. I eventually replaced the tank for I couldn't trust it to not spit out a shred of liner at a most inopportune time.

I encourage you to do what is necessary to find a replacement tank.

Based on the posts I have read in in this and many other forums there are few alternatives once the sealer/liner starts lifting.

I expect that you could have a large portion of the tank cut away so you can manually scrape everything out of the tank. Then have it re-welded or brazed closed and cleaned.

You must be careful with MEK. A chemical respirator, and chemical resistant gloves are required to handle it. It can build up in your system like the old carbon tetrachloride. I once had to clean the stamped lettering off about 6,000 feet of PVC pipe to use as fire detection piping (vesda). MEK worked the best of the things we tried. Later they hired one of the owners sons to clean some more overnight. They piled up the rags and almost burned down the building from spontaneous combustion. That would not have been a good headline " Special hazards fire protection company burns to the ground".

The PO probably didn't do the prep correctly. I used Red Kote on my 38. That was 17 years ago and still going strong. Red Kote recommends using acetone to soften existing liner before applying a recoat of the liner if it's ever necessary. I would recommend trying acetone on your tank to see if that will remove yours.

Good suggestion Art. I sometimes forget that others don't know or appreciate the hazards when handling chemicals. We used boiling MEK to breakdown cured polyurethanes. It was in a well ventilated laboratory fume hood. Any solvent should only be use either outdoors with breathing, eye and skin protection or with proper ventilation indoors. That does not include your home or garage.

I will definitely do that. The rest tank was left alone, but I’ll be working on getting all the sediment out in the next few days.

I’ll have to figure out how to post pictures, but after 4 hours of constant work, I got more then 97% of the old liner out without having to breakdown anything

Well advised information. Luckily I was a firefighter/haz-mat for roughly 20 years. But that actually makes me more dangerous then the general public. I know better, but refuses to listen to myself ..

Sae5,

You will fit well with this group! Many of us know better but do it anyway.

It is good to hear that you have been so successful removing the deteriorated liner. I expect you might have a usable tank.

With respect to filter location, I have mine near the outlet from the gas tank. I installed a shut-off valve just upstream from it so it is very east to change the filter.

I chose that location to protect the fuel pump. I have a more traditional mechanical one on my ”˜37. I expect that you still have the vacuum tank system. My observation from talking with people who have those is that they are very susceptible to dirt.

Great progress!

I was raised a grease monkey and learned how to rebuild carbs when I was 8. My grandpa taught me well.
At the bottom of the vac tank it has a gas shut off. That was a PAIN getting cleaned out for sure.
I was thinking of adding a glass collection cup before the vacuum tank.

The main question I now have is what all the tubes do.. one brings gas from tank into the vacuum tank, the bottom one drains fuel to the carb, the other one is for causing the vacuum but it has a T on it and a chunk of wood shoved into the other side.. not sure if I could just plug off that better then the golf T someone else used.
There is a small little hollowed out plug for air venting.
I will be getting some new cork and cutting gaskets soon. I’m happy this is a something I can use my laser cutter for. Should save a lot in the long run.

Sae5,

You might enjoy reading about my recent rehab efforts of the carb and vacuum tank in my '28 Canopy Express. Here's a link to that story: Fuel issues and my fixes for a '28

Cheers, Dean

The small tube on the "T" that connects to the intake manifold goes to a valve on the dash to control the vacuum windshield wiper motor.

So the top and bottom of the vacuum tank are just soldered on. If you felt adventurous you could unsolder the top to clean it out. I would not unsolder the bottom because if you do not get the top back 100 percent sealed you can get it finish sealed with alternative methods. As for debris getting from the gas tank, the vacuum tank, and the piping into the carburetor you can find a period looking filter that threads into the bottom of the vacuum tank. Tillotson, Carter and Holly made those type of filters.

The top of the vacuum tank is held onto the body by screws, so there's no need to un-solder it.

There's an inner tank that just lifts out after you have the top off. The outer tank (the body of the whole schabang) can be cleaned out with a wire brush and some elbow grease.

See the pics that I posted in my rehab story (click on the link three posts above this one). Those pics show the parts of the '28 vacuum tank.

The innards of the vacuum tank are different for the pre-1928 tanks.

Sae5, does your vacuum tank have four or eight screws in the top? The four screw one is correct for '28 and that's the one that I worked on. The eight screw tank will work on a '28, but the innards are more complicated than in the four screw model.

All my best, Dean

Makes sense.. I don’t have one of those.. just a hand crank at the top for the blade..

it has the 4 screws with the canister the float comes out with all in one piece.
I have already pulled it apart and cleaned it up. I just placed an order for cork gaskets that I can custom cut for it.
I will definitely check out your build thread. The wife wants me to do a YouTube build thread but I’m not good at remembering to film things as I go.. I is an y remember about a day or so afterwards I meant to do it..
the only thing that is not OEM on this vehicle seems to be some wiring someone else replaced. The engine still turns and just needs a little TLC to get her started.

I also don't think along the 'film as you go' lines, so I take a bunch of photos instead. I find the photos remind me of the details of what I did and that makes it easier to do a write up of the project after the fact.

Another good thing about taking lots of photos is that you can assemble them into a photo album showing your work and take the album to car shows. Folks love to see the process of resurrecting an old vehicle.

As for getting your engine started, here's a previous post of mine where I describe how I time and start my '28 engines: Timing and starting a 1928 Chevy engine

Ever onward! Dean

I have done some reading on how to start the vehicle.. It's like playing with a Rubik's cube, and juggling at the same time.
The one thing that got me laughing is that the keys are for only locking/unlocking the wheel.
Basically just unlock it and throw them the back seat so you don't lock the wheel on accident.