• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Gas tank residue?

Share this page

Nelson

Nelson

Jedi Warrior
Country flag
Offline
My Sprite was last run back in '73. My restoration is now very near to completion and I am just about ready to fire up the engine again. I just realized that I may have a problem with the gas tank. There was some gas in the tank when I put the car into hibernation but I have no idea how much. When I pulled the drain plug several years ago nothing came out. Now I am concerned that there may be some residue that will come loose when I put new gas in the tank. There is a filter before the input of the Facet fuel pump I have mounted at the tank. Do I need to be concerned about crud creating a problem? If so, do I need to remove the tank and flush it or is there a less troublesome way?
 
It's a personal choice on how to proceed. Were it my car, I would drop the tank and first fill it with a gallon or two of thin paint stripper. Plug the openings and slosh that around for several days. After that, you can rinse the tank with a strong caustic cleaner to remove the remaining varnish and to remove residual paint thinner. After that, rinse with water and allow the tank to completely dry out.

Use a coarse filter before the Facet, not a fine paper filter. The pump can push much better than pull and any rust scale and chunks of varnish are likely to quickly plug a paper filter on the suction line. A finer paper filter placed right before the carbs will be very effective at catching the fine stuff and easy to check. I use the disposable, transparent filters commonly used on old air cooled VWs.
 
I would drop the tank and take it to a radiator shop and have them flush it and check for leaks...

I didn't do this with my car and paid the price - old gas "varnish" plays heck with valves...

cd
 
Back in the day, the remedy for an old "cruddy" tank was to flush it with a gallon of lacquer thinner and a box full of BBs! Pour the thinner into the tank along with the BBs, seal the orifices and shake, rattle and roll the tank vigorously. Drain the sludge, and with a wet/dry vac suck out remaining sludge and BBs. That is the "old school" way and some may poo poo it, but it DOES take lacquer thinner to break down the fuel deposits which are basically lacquer!!
 
bugimike said:
but it DOES take lacquer thinner to break down the fuel deposits which are basically lacquer!!
Click to expand...

I agree. I suggested paint thinner but the lacquer thinner may be a less expensive option. The BBs (or rocks, nuts, bolts, etc.) to agitate things certainly will help a lot.
 
The lacquer thinner sounds like it would be a good solvent. I'm concerned though about using my shopvac to suck out any sludge. It seems to me that the vapors and the possible arcs in the electric motor could pose a nasty situation. I think I would do better by doing another batch of the thinner to dissolve any remaining sludge from the first batch.
 
You really don't want to get lacquer thinner into your shop vac. You probably don't absolutely need to use it anyway; just make sure the inside of the tank is dry and shake out any of the loose material you might have added.

There are sealers you can get; see Eastwood for example. I have no experience with them, but I'm sure someone here does and can comment.
 
I have used the Kreme and POR-15 gas tank kits. Of the two I prefer POR. There are also kits from "Red Kote" and I noticed recently that Caswell (the guys who sell DIY plating kits) sell an epoxy tank lining kit.

My advice for now is to clean the tank and see if you need to seal it. If the rust inside isn't bad enough to have created a pin hole, just remove the varnish. If cleaning the inside of the tank reveals pin holes, come back and use the search feature here for old threads about tank linings. Don't limit yourself to the Spridget forum... the topic comes up in each section of this board.

I agree. Don't use the shop vac. If you pour most of the grunge out, a follow up with water based caustic cleaner will allow you to rinse the remaining stuff out with water. I've had good results recently using ZEP industrial degreaser from Home Depot. It appears to be as strong as POR-15's "Marine Clean" at way less than 1/2 the cost.
 
After all the time and money I have put into restoring my Sprite I think it best to do a full job on my tank. I will get the POR-15 supplies and do the whole procedure. At least with this size of tank I won't need to buy their kit for a 25 gallon tank. I just wish I had thought about this before I got so close to finishing my car. I appreciate all the input from you guys.
 
Hey I'd be brave and add a little gas. Slosh it around a bit and see what issues from the drain plug.
Rebuilt an XKE once and just before completion realized that the tank held something far more suitable for furniture refinishing than for motor fuel. Did nothing more than a good flushing with gas and filters on the fuel line. Cleaned filters for a short time and all was well. XKE has a coarse pickup screen in the tank.
If things look bad from the drain plug or give you trouble later its not that hard to remove a tank.
KA.
 
make sure it's clean - Mark (Abarth69) may wander by this conversation and tell you about the Aston Martin DB? with the rebuilt engine that is sitting in his dad's barn (being worked on - not abandoned) The new engine ran for 5 minutes and then quit due to bad gas. make sure it's clean - I'd go the rad shop route, it's quick and sure
 
In recent years I have had several tanks treated with the POR15 kit. I have also had bad experiences with radiator shops. I found a local guy who will do the whole POR15 job, clean, rust treat and seal for $75. That's about the same those rad shops want and you don't know what they use or how they do it. Since the POR15 kit is $50 or so, that seems like pretty reasonable for the amount of labor and time involved.
 
After reading subsequent posts to mine, I must clarify that I did NOT mean use the wet/dry vac to get the lacquer thinner out of the tank (that would make short work of the vac!!), but to remove the BBs and last bits of reside...the lacquer thinner will evaporate quite rapidly leaving a "dusty, rusty" residue which one can do a final cleaning up of with the vac (Even with a brush attachment!).
 
Back
Top