Additional stainless steel tank
Dear all,
i am considering an additional 100L fuel tank onboard 47/013 VERA under the owners berth in the aft cabin. My feeling is that it should be made from stainless steel like the original ones (that are still in bristol condition after all these years), but i am not sure, as this must surely be done with the proper steel grade (1.4404 maybe?). What grade of stainless was used at the Nautor yard in the 70th? Is plastic an alternative? Can anyone (Professor!) help me out here with some thorough information? Does anybody know about a trustworthy and affordable welder/ custom tank builder in Europe?
Kind regards, Michael 47013 / VERA

Dear Michael
The suggested material 1.4404 is correct. A plastic tank is a possibility if you can find a prefabricated and approved one that fits the space. There has been some discussion about the effects of high fuel return temperatures on plastic tanks, a stainless tank would not be affected by this.
It is recommended that the Recreational Craft Directive standard ISO 10088 for permanently installed fuel systems is followed.
You need also to consider the following - secure attachment of the tank, location and arrangement for fuel fill and vent lines, fuel feed and return lines, fuel shut-off valve, electrical grounding, tank level gauge if any.
Kind regards
Lars

Dear Lars,

great advice, as always. I will go with stainless then. Lets see, if i can find a good welder for that, as the optimum shape will be weird to look at...

thanks again, and good night, Michael

Dear all, i am considering an additional 100L fuel tank onboard 47/013 VERA under the owners berth in the aft cabin. My feeling is that it should be made from stainless steel like the original ones (that are still in bristol condition after all these years), but i am not sure, as this must surely be done with the proper steel grade (1.4404 maybe?). What grade of stainless was used at the Nautor yard in the 70th? Is plastic an alternative? Can anyone (Professor!) help me out here with some thorough information? Does anybody know about a trustworthy and affordable welder/ custom tank builder in Europe? Kind regards, Michael 47013 / VERA

May I suggest Monel? It can be thin because it does not corrode and the seams can be folded and then soldered using low temperature tin solder. The cost of material is high, but it is very easy to work and no welding is involved. Any shop that does sheet metal work can make a tank with folded seams. Not so many shops can make a tank with welded edges and handle the distortion created by welding. A 8 inch diameter clean-out should be provided. After making the tank it should be filled with water and pressure tested for leaks. If you consider the cost of the entire job,including installation, the higher cost of material makes little difference. It is old technology and well proven. If you ever find a leak, soft solder and a propane torch will fix it.
Pete