How To: Ford CMP "Blitz" miscellany

[Jacques Reed]

Hi Hanno,

Thought today would try some magnetism experiments as per attached photos.
It is a lot easier to find out if it works on a workbench than trying to retrieve balls and steel bars out of a fuel tank!

I used a sheet of 1.1mm galvanized steel as a test. A bit thinner steel than a CMP fuel tank.

Unfortunately the results were disappointing:

Using seven 25mm diameter CV joint balls resulted in very little extra holding power than just the magnet alone. That could be caused though by the alloy used to make the balls just as stainless steel is non-magnetic.

I then tried a piece of steel bar 40 mm wide, by 15 mm thick, by 160 mm long. The holding power was significantly increased but I doubt it would be enough to pull a dent out of a tank. I was able to break it free with what I estimate was about 15kg of force.

So it's "back to the drawing board"

One good thing is a PDR technician returned my call and is actually willing to at least have a look at it in the New Year. Many businesses shut down for a few weeks during the December January period here in Australia so I will see what can be done in January. I am thinking if the hot glue method has the holding power it will do the job. Just have to see what his opinion is and what the cost estimate is if he can do it.

Will update this when the technician attends.

Cheers,

[Bob Carriere]

Had a look at the dents you are trying to pull out.

Have you tried soldering a brass bolt or copper tab ??? then use the typical dent puller.

We have had good success at the barn soldering pin holes in tank bottoms... we dimple the pin hole with a small ball pein hammer and clean the area to bare metal
.... we use an electrical soldering iron ......once sanded down they do not even show and do not leak. So soldering should give a very good bond...... to attach a puller to.

You maybe able to pull enough to be able to finish the job by using solder to fill any indentation left... then sand down.

We used an acid solution to clean out the inside and once rinsed and sand blasted on the outside we discovered a lot of pin holes..... then we inserted a 12v bulb inside the tank and closed the barn doors....... there were a whole bunch of shinning little stars which were not seen in daylight.... all were dimpled and soldered. For good measure we used a gas tank sealer on the inside...... a real messy job but worthwhile.

Cheers

[gjamo]

Jacques you may even consider Phil's method and cut the end out before panel beating the bottom and rewelding a plate in.
http://www.mapleleafup.net/forums/sh...highlight=tank

[Phil Waterman]

Hi All

Please anyone considering repair of fuel tank, remember the risk of fire or explosion.

The tank I recently opened with plasma torch was known to have been open (no cap) to the elements for many years. Had there been any hint of fuel, probably would have filled the tank with water while cutting.

I know that people who have responded to this thread are well aware of the risks, I'm more concerned with people doing a web search on fuel tank repair not being aware of the hazards.

Cheers Phil

[Jacques Reed]

Originally Posted by Bob Carriere

Had a look at the dents you are trying to pull out.

Have you tried soldering a brass bolt or copper tab ??? then use the typical dent puller.

We have had good success at the barn soldering pin holes in tank bottoms... we dimple the pin hole with a small ball pein hammer and clean the area to bare metal
.... we use an electrical soldering iron ......once sanded down they do not even show and do not leak. So soldering should give a very good bond...... to attach a puller to.

You maybe able to pull enough to be able to finish the job by using solder to fill any indentation left... then sand down.

We used an acid solution to clean out the inside and once rinsed and sand blasted on the outside we discovered a lot of pin holes..... then we inserted a 12v bulb inside the tank and closed the barn doors....... there were a whole bunch of shinning little stars which were not seen in daylight.... all were dimpled and soldered. For good measure we used a gas tank sealer on the inside...... a real messy job but worthwhile.

Cheers

Hi Bob,

Haven't tried that method with a brass bolt or copper tab but it sounds like it is definitely worth a try. I am sure it will have a lot more holding power if the bolt or tab has a reasonable size area. I will give it a try on the bench first.

I like the idea too, that not a lot of heat or an open flame is used in soldering.

I repaired a pinhole in the other tank on the top where the retainer strap had rubbed a hole in the tank similar to your method. Dimpled it slightly and filled it with JB Weld. Great stuff.
At that time I didn't have a decent size electrical soldering iron and there was no way I wanted an open flame from a Bernz-O-Matic near a hole into a tank, even though the tank had been empty for years and washed our just prior to the repair. To do it again I would consider your method with the big electric soldering iron I now have.

Anyway guys, this thread has been very helpful and all suggestions have been gratefully received. I, and many others, have a better idea of the issues of repairing a dent in an enclosed tank. I even enjoyed my magnetic experiment that didn't work. Just more info to add to the wealth of information and ideas out there.

As Phil so rightly posted just be careful around fuel tanks with whatever repairs you do to it. Most of us know that but there is always someone perhaps new to auto repairs or restoration who doesn't realize the risks.

Have a safe and Merry Christmas and I will continue on after the Holidays with trying to get that darn dent out!

Cheers,

[Hanno Spoelstra]

Originally Posted by Jacques Reed

Anyway guys, this thread has been very helpful and all suggestions have been gratefully received. I, and many others, have a better idea of the issues of repairing a dent in an enclosed tank. I even enjoyed my magnetic experiment that didn't work. Just more info to add to the wealth of information and ideas out there.

Jacques, I like your inquisitive approach to solve problems and enjoy reading about it.

Thank you very much for your informative posts, I hope you continue to share your insights in the new year. Enjoy the Christmas break!

regards,
Hanno

[Ken Hughes]

You would need to purge the tank with exhaust gasses from a vehicle for a couple of hours before you did anything with heat,one old way from my panel beating days was to clean the area thats damaged and solder a stick of body solder on to the damaged area let it cool and pull the stick and hopefully the dent will come out,modern body shops have dent pullers that weld a stud on and can be pulled as well.
The inside of the tank is soldered all over so that might be a problem down the track with heating it. it may be better to fill the dent or the big extreme make a new tank which i have done.

[sth65pac]

Gents,

Not so sure about the dates of the tabs appearing.

My truck has the plate on the front (its a 1942) and the other 1942 cowl (truck now deceased) I have, has the tabs described on the front. (sorry hard to see with a very small sized picture!!!)

These pictures are over 10 years old.

Cheers,

Ian

[Jacques Reed]

Hi Ian,

I am not sure but the one bracket on the right side of the cowl in your photo looks like a Tac sign holder similar to the one in the attached photo.

My first truck lacked the welded on tabs for the Bridge disk also, but had the Tac sign bracket on the left side of the front cowl. The Bridge weight limit was painted on the top of the right hand cowl.

The spacing on my TAC sign mounting holes are 4" apart but the bridge disk mounting holes are 5" apart. That might not mean anything, however, depending on the diameter of a bridge disk

Perhaps someone more learned in vehicle markings can shed some more light on it.

Cheers,