Thread: Box trailer weather tight door seal design - help required

I am looking to build an enclosed box trailer. It will have large gull wing doors on the rear and the two sides.
I will be building the support frame out of 40mm SHS, and the door frames most likely out of 24mm SHS, all clad with aluminum sheet.
The top hinge will be one of the continuous types with the weather seal rubber insert.

Anyone got any experience with the best way to create a weather tight door seal around the rest of the door (ie best rubber extrusion to use, does it need some other aluminum support extrusion, can the aluminum sheeting on the door be left proud of the frame and a rubber extrusion slipped over the aluminum sheeting, ???) ?

I drove a nissan truck with 6m box body with gull wing doors... if you make the first say 200mm of box ridgid that makes life much easier as you can pull down tight the moving bit... it had simple hook and cam over latch,one at each end of door... it actually had another in centre being such a long span. pretty much any soft squishy type of rubber seal will work if you can pull the top/outer bit down firmly.

Have a look at some Teardrop forums, lots of people build their own and there’s lots of info on sealing doors of all shapes and sizes.

Originally Posted by hotbarrels

Anyone got any experience with the best way to create a weather tight door seal around the rest of the door

I'm in the metal industry and come across a job like this... sometimes.

For any large box, if your material, folding and return are thick enough (e.g 3mm (or thicker) ali chequer plate at say 50mm fold + 20mm return or larger)
I wouldn't use any box section (SHS).
folding and return themselves act as SHS and are more than strong enough and this would cut down your fabrication & welding costs.

Ask your sheetmetal guy to include at least 1 return fold on the frame box
you could have 2 return folds for a better seal but this could push the cost up

Originally Posted by hotbarrels

best rubber extrusion to use, does it need some other aluminum support extrusion, can the aluminum sheeting on the door be left proud of the frame and a rubber extrusion slipped over the aluminum sheeting, ???) ?

Rubber seal,,, I can't remember the name but it's the same stuff we use for boat hatch

aluminum support extrusion ... personally I wouldn't use extrusion but you can if you want to


aluminum sheeting on the door be left proud of the frame and a rubber extrusion slipped over the aluminum sheeting.... I guess you could but you need to fix them together

There's some stuff that looks sort of like a figure 8 shape, it's used to make ute tailgates dust tight. That would work grand as you leave a gap for the seal to compress into and job done.

There's a really good place that I deal with for seals and bits and pieces. It's called 'Co Mac'. They have every shape of seal in creation as well as anything else you might need to build pretty much anything in the transport field.

They are bloody great to deal with too. Find it in thier catalogue. Order it, it will be on your doorstep the next day.

Originally Posted by 2post

Have a look at some Teardrop forums, lots of people build their own and there’s lots of info on sealing doors of all shapes and sizes.

Yea, I have been looking at them. Most are all complaining about the leaks they are getting

Originally Posted by Snap 4T

I'm in the metal industry and come across a job like this... sometimes.

For any large box, if your material, folding and return are thick enough (e.g 3mm (or thicker) ali chequer plate at say 50mm fold + 20mm return or larger)
I wouldn't use any box section (SHS).
folding and return themselves act as SHS and are more than strong enough and this would cut down your fabrication & welding costs.

I need the box section structure to support the weight of the pizza oven that is being mounted inside the trailer, so I think it's more economical in the long run to use that structure to support the doors.


First price is to come up with a seal design that is mounted to the door as it is less likely to get damaged by things being loaded onto the trailer.
Still hunting for the ideal solution.