Pontoon Questions: Jacking it up while on trailer? & What's this called?

[ChazzL]

I'm wanting to jack the trailer up a few inches so I can work on the bunks. The bunks are longer than the back of the tubes so I cant brace up and jack the bottoms of the tubes. So my questions are:
1) Is the welded box at the end of the tubes (for mounting transducers, etc.) strong enough to put a jack under? (#1b in photo).
2) What is this called and is it strong enough to put a jack under? (#2 in pic).
3) What about putting a 2X6 across these 3 of joists on each side to use as a base for lifting?
Thanks for any help. Would like to hear opinions.

 

[jlh3rd]

1. - no, you'll bend it.
2. - that's the bottom of your motor pod. It is not structural...you'll most likely collapse it.
3. - yes..that can work. The ribs (C channels) are a good support structure.
And the 2x6 spreads the load.
Furthermore:
the toons are normally built in welded sections. Each section is water tight which means there is a bulkhead at that seam. Another good structural point. Be careful lifting/supporting between these sections, or you'll end up like the picture.

 

[ChazzL]

1. - no, you'll bend it.
2. - that's the bottom of your motor pod. It is not structural...you'll most likely collapse it.
3. - yes..that can work. The ribs (C channels) are a good support structure.
And the 2x6 spreads the load.
Furthermore:
the toons are normally built in welded sections. Each section is water tight which means there is a bulkhead at that seam. Another good structural point. Be careful lifting/supporting between these sections, or you'll end up like the picture.

Thanks. Those pics don't look good. If I cut a foot off the back of the bunks is it structurally strong enough to jack the boat of at the rear end of the tubes?
(I'm going to go with the #2 option, but curious if I can use the rear of the tubes).

 

[Scott Danforth]

Jack it up from the deck, not the tubes

Your bunk trailer only works because it supports the whole tube

 

[flashback]

why not launch the boat and tie up on a pier, then do the trailer work.