Fabrication advice

[KompetentKrew]

Hello,

My 25-year-old Victron inverter charger recently died, and I replaced it with the current model.

The new charger is different dimensions than the new one - it is taller and slimmer.

The mounting holes on the new charger are about 40mm wider apart than on the old one, but I want to use the same mounting studs.

The reason for this is because the charger is mounted to the holding tank. There are four studs that come out the side of the holding tank - I think they're bolts, and the heads of the bolts are epoxied or sikaflexed in place, but I don't want to disturb them because they don't leak and it's stinky in there.

I will therefore need to make some kind of mount / adaptor to mount the new inverter to these existing studs.

There is a lip above the top of the old charger, like a fiddle on the shelf above it, and because the new charger is taller it will need to be held out from the mounting studs by 1cm or so. (2cm is fine)

I can think of two approaches to making the mounts:

• The first approach is to cut a steel plate the size of the new inverter - it is a carrier plate that the new inverter bolts to.
  • Then make up a couple of legs or brackets which match the mounting holes of the old inverter.
  • The legs / brackets are welded to the carrier plate.
  • This can be made in mild steel and spray painted, because it's in a dry locker
  • However I need to pay a fabricator to do the job because I don't have a welder, nor the tools for cutting the plate or bending the brackets.
  • (I hoped to cut and adapt the case of the old inverter for the carrier, but it is aluminium and thus I think it's too expensive to have welded?)
• The second approach is to make a pair of vertical hangers from aluminium channel (U cross section)
  • These each need to be a bit more than 20mm wide - to allow for 40mm wider mounting points, plus the diameters of the mounting holes
  • They bolt to the old mounting studs at the back, then the new inverter bolts on the front
  • This a great solution, because it requires only two 40cm lengths of aluminium channel and 4 holes drilled in it
  • EXCEPT! A section of the channel needs to be cut out of the channel to accommodate the lip in the shelf, see diagram below

I am favouring the second solution, because aluminium channel is very cheap, I have a drill and I can do that part myself. The red circles on the diagram show the holes to fit the existing mounting bolts (that come out of the holding tank); on the other side of each hanger I will drill holes to mount the new charger.

The part that I'm concerned about is cutting along the dotted line, so that the hangers will fit over the lip:

• I guess 2mm thick aluminium channel will be strong enough to support a 10kg charger?
• Can I cut this with a hacksaw?
• I have a Fein multitool, but I don't think that's powerful enough to cut the aluminium?
• I thought about drilling a series of holes with a fine bit as perforations / guides, before cutting with a hacksaw.

I'd appreciate any thoughts or critique. I apologise if I'm being dumb or overcomplicating matters. Maybe I've overlooked an easy way to do this?

 

[KompetentKrew]

The existing four studs, and the lip under which the old charger sat:

 

[SlowlyButSurely]

If it were me I would simply cut the protruding bolts off as short as possible and glue a piece of plywood, suitably rebated to accommodate the studs, to the side of the tank and fix the new charger to that with screws or sometimes I use shock cord or cable ties for this sort of thing.

 

[Spirit (of Glenans)]

I would lean towards timber as a solution to this problem
Much easier to work with, and no need for expensive marine material as it's in a dry, well protected part of the boat.
If , however, you go ahead with aluminium alloy 'U'-channel, it will be very easy to work it with a hacksaw and drill. An electric jigsaw would be even better.

 

[Stemar]

I would lean towards timber as a solution to this problem

My first though as well.

Do the black bits come off? If so, just drill it so it's held on by the bolts. If not, it may be easier to use thicker ply stuck to the grp with CT1 or similar

 

[Concerto]

Plywood is how I would solve the problem. Use the existing studs to hole it in place and then screw the new inverter to the plywood. Simple, quick and inexpensive to do. Seal the plywood edges should be a wise move as well.