I Cant figure out how to do this

[Tony Jacuzzi]

[SIZE=10pt]So I have to replace the front boom tube, it is mounted with two holes drilled through the boom and into the front block which is mounted not to the floor but to the front bulkhead, then it has 2 holes on each end of the boom to attach the sponsons, the stubs are tapped . The stub hole and the main boom holes are offset (eg not in the same line). How in the heck do I do this accurately I can’t get my head around how to do this to get everything to line up. I was thinking that I should probably get the new boom drilled at the stubs and lined up to mount the sponsons, then drill the main mounting holes? Im lost appreciate any input[/SIZE]

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[steve wood]

2 holes in each stub is over kill. drill for the tub first,then mount the sponsons. I would drill a new hole in the stubs between the 2 that are there now. I have a tool that I made that is a v block with a bolt with a hole through the center that clamps the tube to the v, the bolt is centered up on the tube, and you use a hand drill to drill through the bolt and tube. if you assemble both the sponsons to the boat and set the v block on a parallel, you can be real consistent in re drilling new tubes

 

[Terry Keeley]

Hopefully the holes in the sponson tubes are at some measurable/consistent distance apart. If so I would measure then transfer the dimensions to the outer tube and drill for the sponson tube holes first.

Put some set screws in the front bulkhead holes leaving them hang out just a bit.

Assemble the sponsons on the boat with front/rear tubes & check alignment. Put the boat nose down on the table and using a small block of wood gently tap on the front tube. The set screws should transfer the hole location to the front tube, a little "dykem blue" might help.

Steve's way would be easier if you don't mind extra holes in your sonson tubes, or contact whoever made the hull and get some dimensions.