RN Scuttle Mounted Fuel Tank "A Baffling Problem"

[Steve Parkin]

I decided to replace the petrol  tap on our 1932 RN with a scuttle mounted tank (April 1932). My idea was to replace its simple modern chrome tap with and "original design" Ewarts tap  that can be operated from within the car (complete with reserve setting).  I managed to purchase a replacement Ewarts tap via eBay and I followed the well documented instructions from Roger Bateman of DA7C to refurbish it with O rings. As he states, to get the tank into place you have to remove some of the tank mountings. 

Having removed three bolts, and checking the position of the replacement tap, I decided to go one stage further and investigate the condition of the tank and scuttle. I removed the fourth bolt and took out the tank. Behind was a spanner hidden that had probably been in there some time, certainly before we purchased Harvey over 5 years ago . But then, as I moved to tank to put it in a safe place I heard an ominous rattle - something was loose inside the tank! It wasn't another spanner but a baffle that was lying in the bottom of the tank.

The tank looks in sound condition, and is probably not that old, but there are marks where the baffle plate used to be located and it has obviously been on the move. 

The obvious question is what to do next? 

Below is a picture that I managed to take through the filling port using the wonders of modern smart phones. The original location of the baffle is clear. 

Questions:

• Was the baffle plate glued in place? The location is on the centreline of the tank (and vehicle).   
  
• What material is our tank and what was the original construction material back in 1932?
  
• How can I put it back in place?
  
• Was a baffle plate part of the original design
  

I would welcome comments. 

The body fittings on the tank are riveted in place and there is a single seam along the top of the tank. 

   

[Duncan Grimmond]

I would have expected the baffle to be soldered into place, that's what I do when making petrol tanks. Your difficulty will be putting the baffle into the right position and hoping to re-solder it into place. (no flame, a big copper iron only, you don't want to end up wearing it!)
If it's not causing you problems as you lurch round corners I would definitely leave well alone.
If it is causing problems probably the best way to sort it would be to take one end off so that you can see what you are doing.

["Slack Alice" Simon]

A long time ago, I had the same problem with my Cambridge tank.

I cut a three sided fist sized hole in the back of the tank, allowing me to position the baffle in front of 1/8th holes drilled in the tank, 2 each front and rear.

With the baffle in place, drilled through the holes to make corresponding holes in the flange in the baffle.   Countersunk self tappers through, to hold the baffle in place.

Solder over the heads of the screws, bend the hole flap back roughly into place, solder a tinplate patch over the area.

Though crude, it has stayed in place for 40 years.


Provided some amusement, too.

When we did our first JoGLE run in '82, my Managing Director "sponsored" us to the tune of a tank of fuel from the company pump.

When it reached the half way mark, it started running out through my badly soldered patch, all over his highly polished shoes.

He bravely carried on, and we sped off to catch the fuel in a washing up bowl.

Being impecunious, we had never had enough fuel in the tank - I think they hold 10 gallons - to get near the patch to discover that it wasn't as good as it should be!

[Chris Garner]

Steve, I've recently had the same problem with an Ulster tank where the soldered interior baffle had become detached.
Rather than try to sort it myself, perhaps not with the best of tools, I let my local radiator man sort it. He took off a side panel, reattached the baffle, re-soldered the panel back in and checked over the whole tank for leaks. It also needed a small amount of work on the filler neck. Job sorted and confident the work is accurate.

[Steve Parkin]

Thanks for all the comments so far. At the moment I am exploring the option Duncan mentioned but Chris identified. I'm talking to a local metalworker who is familiar with working on fuel tanks about removing one the end of the tank and fixing the baffle back in place. I don't like the idea of a rattling metal plate being in the tank (although it probably has been there for some time). We haven't had fuel starvation issues but we tend to make sure the tank being gravity fed is reasonably full.

It does look as though the tank is soldered (not braised) although I am leaving the "expert" to sort that one out.  Also, I'm taking the opportunity paint the scuttle behand the tank and replace the felt padding I found behind and below the tank.

[Chris Garner]

Steve, I think you'll find the tank is soldered, not brazed. Best of luck!
C.

[john williams]

Felt padding behind the tank is to be avoided. It soaks up water, and will rust through the bottom of your tank. It was never fitted originally.

[Duncan Grimmond]

"It soaks up water, and will rust through the bottom of your tank."
Wise words indeed.

[Chris Garner]

Interesting comment, John, on the felt ring. I've had two cars which were fitted with a continuous ring of felt like material behind the front flange of the tank, butting up to the scuttle. I know it's not listed in the Spare Parts handbooks but it did seem custom made. I wonder if it was an afterpart manufactured by a spares company. I didn't refit them for the same reason as you give, but did wonder about fretting between the tank & scuttle. I may still even have one of them amongst my hoard of spares!

[Parazine]

"It soaks up water, and will rust through the bottom of your tank."
Wise words indeed.

+1 on that. My RM Box was perilously thin on the scuttle for just this reason when I took the tank out in the early eighties.