Gidday Twink, you old dog ... :iconwink:
awesome ratbag! how's the trailer going?
Getting there, thanks mate. Mounting it to the existing lid is a bit problematic. Nothing that can't be fixed, but it shouldn't have to be. Once again, poor design of the tent assembly.
I could redesign the base board in about 10 minutes so that these problems wouldn't exist.
Use "H" section aluminium channel for joining the two halves of the base board together (i.e. an "I" beam ... instead of reinforcing a butt join with a length of the base board material). Screw to both top and bottom on both sides using particle board screws into the 9 ply marine ply base board, offset so that they don't hit each other.
Then use an "h" section aluminium extrusion for the framing of the trailer bed access hatch. Use an aluminium right angle extrusion to frame the hatch part for wear resistance and accuracy of fit.
Use half-hard or hard aluminium extrusions to get the required strength.
Done. No more protrusions under the bottom of the base board, and no need for the 40 x 20 steel box section that forms the frame for the access hatch, so money saved there.
mounted the basket today, (took all bloody weekend!) will be getting it modified soon (if anyone knows a boilermakers that's looking for beer let me know!) ladders are ready to be welded up. will be getting the ladders and basket sandblasted and powder coated once they're welded up!
I know what you mean! "Simple" things often take far longer than one thinks they will - removing body clips holding the front 'spats' on my car springs to mind ...

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While powder coating is the thing of the moment (has been for about 20 years ... ), I prefer hot dip galvanising for this sort of stuff. The gal. coating is tougher in use and resists abrasion and 'fracture' of the coating far better. It also doesn't miss any bits the way powder coating and electrophoretic coating can.
Just FWIW.