Boat trailer project

[excossack]

I have a fibre glass Dory style boat, it measures 9ft long by 4ft wide.
I am planning on using a pair of 350kg suspension units and 10" wheels.
Along with the suspension units, I am going to buy the suspension beam as well as this has the mounting plates already mounted.

My question it. What thickness of box section should I be using?
I dont want it flimsy, but at the same time not too heavy.

As I only have a small MIG welder Clarke 100EN Turbo, I intend to tack weld the the trailer up and either ask a mate with a bigger MIG to weld it up or borrow his welder.

 

[madkayaker]

under new regulations you are no longer allowed to build "new" trailers without them being type approved. your mig is probability a bit small for the task i think my trailer is made from 50x50mm box 2mm thick

 

[excossack]

I could rebuild an old trailer then ? with new hubs etc?? ;-)
I thought my Mig would be too small.

 

[brightspark]

I could rebuild an old trailer then ? with new hubs etc?? ;-)
I thought my Mig would be too small.

just build a new one and say its old and been looked after the law on thems stupid no one can prove any diffrent

 

[SC_BK]

New suspension units etc aren't that cheap, I always see used boat trailers going for not much money

 

[cumbriasteve]

50 x 50 box is about the norm, be careful they dont supply the thin wall though, your mig would do for tacks and getting the shape together but a bit more power for welding is required, I always use my trusty arc welder when making trailer chassis.

 

[excossack]

The suspension units ive seen are 350kg and are around £70 plus P&P and then the suspension beam for around £20 + P&P

I was thinking along the lines of 50mmx50mm

 

[Jeepster]

under new regulations you are no longer allowed to build "new" trailers without them being type approved. your mig is probability a bit small for the task i think my trailer is made from 50x50mm box 2mm thick

The new regulations dont start until september 2012, so you still have time to beat the deadline. Of course if you build it yourself you can simply make up a date that you made it and say it was made long before any regulations came in so its not a deal breaker. I am building one at the moment and if the regulations make it necessary I will simply say it was made back in the 90's
Besides, as far as I am aware the new regulations only cover commercially made trailers, not home-builds but that would need clarification as I cant be 100% sure.

 

[Jeepster]

50 x 50 box is about the norm, be careful they dont supply the thin wall though, your mig would do for tacks and getting the shape together but a bit more power for welding is required, I always use my trusty arc welder when making trailer chassis.

50x50x2 seems very weak steel box to make a boat trailer with, unless its a very lightweight boat?
I'm using 80x40x3 for the main side rails and the two removable cross members of the front I frame, 60x40x3 for the two swingbeams, 80x80x3.5 for the removable longitudal member of the front I frame and the winchpost, and my boat only weighs about 450kg...It may be a little over engineered but it aint gonna fall apart in a hurry!

 

[Jeepster]

New suspension units etc aren't that cheap, I always see used boat trailers going for not much money

Forget buying expensive suspension units...Just get yourself a cheap caravan chassis on ebay and you will have a heavy duty braked axle with built in independant suspension and a heavy duty braked trailer hitch...You can ditch the rest as it will usually be 2-2.5mm galvanised pressed steel chassis rails and far too flexible for a boat trailer unless you add lots of crossmembers to stiffen in up, plus its not the best stuff to weld onto so it would have to bolted together.
There are aluminium caravan chassis as well which would have to be bolted together anyway unless you have a TiG welder and can obtain pure Argon gas.

 

[madkayaker]

The new regulations dont start until september 2012, so you still have time to beat the deadline. Of course if you build it yourself you can simply make up a date that you made it and say it was made long before any regulations came in so its not a deal breaker. I am building one at the moment and if the regulations make it necessary I will simply say it was made back in the 90's
Besides, as far as I am aware the new regulations only cover commercially made trailers, not home-builds but that would need clarification as I cant be 100% sure.

it was my understanding the regulations applied to all trailers and ones built for commercial reasons had to have engineering drawing and the like to get type approval and one off trailers would be assessed singly. I had thought the regs came in last october?

 

[Jeepster]

it was my understanding the regulations applied to all trailers and ones built for commercial reasons had to have engineering drawing and the like to get type approval and one off trailers would be assessed singly. I had thought the regs came in last october?

Only partially, the full regs start in September, from either the 17th or the 26th. Somewhere around then anyway...After that is when you can expect the old bill to start getting hot on trailers and pulling anyone with a trailer at roadside checkpoints to check them out.

 

[gav0994]

Only partially, the full regs start in September, from either the 17th or the 26th. Somewhere around then anyway...After that is when you can expect the old bill to start getting hot on trailers and pulling anyone with a trailer at roadside checkpoints to check them out.

Realistically the "old bill" won't start pulling anyone with a trailer to check them as 95% of police officers have a very small knowledge of road traffic legislation and are scared to put it into practice because the fear getting it wrong.

Plus, there is hardly enough cops on the streets as it is to deal with crime, let alone minor, pointless EU legislation that prevents Joe bloggs/small businesses manufacturing and towing a trailer with an EU number stamped on it.