Potential next boat project: attn people smart with metal stuff.

Evan B

Bobber Downey Jr.
Staff member
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My ocean boat has a radar arch tower that mostly does the job. That said, it's pretty flimsy and can shake quite a bit when running in chop, which can be exacerbated when loaded with a bunch of tuna or halibut rods.

You can kinda see it here.
1000009241.jpg
It's pretty light Guage tubing in I think maybe 1" diameter.

What I want is a much more heavy duty 2" tubing rig where I can also form a fiberglass top to stick on it. Here is a slightly bigger version of my same boat with exactly what I want to do.
1000009683.png
1000009684.png

I know someone with a pipe bender capable of doing 2" pipe that I can use, but he isn't going to have much to offer as far as how to design and execute. I also know a few people who can assist with the tig welding.

Anyone done something like this before? I want to draft up a design, but not having ever done something like this before, I don't even know where to start.
 
I don't even know where to start.


Start by measuring the existing tower, look at where you want the new one to go, look at mounting areas/access, measure measure and measure some more.
 
We had a student in welding design and build a somewhat similar project with round tubing for a fancy job trailer rack.
He used CAD. As I recall it went something like:
Set a datum point for vertical, and centerline alignment and a zero station on the boat, trailer in his case.
Measure/Reference all mounting points on the craft to this framework, up and offset. Use a protractor or other precision tool to measure angles.
Set up the datum, alignment and then build the hard mounting surfaces in CAD.
Design your dream rack using the CAD tools. We had a welding utility plug in. Listed all the pipe cuts, bend locations and bevels, pretty cool. Allowed for strength testing too.
He measured, cut, bent and jig welded some. Some pieces he sent to automated machines.
You seem pretty do it yourself, but maybe someone down at a local CC would be willing to help draw it up, print a couple detail sheets, and even prepare a bar list. This was this students "with honors " project. I still see the local contractor using that rack. Makes me smile.
 
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We had a student in welding design and build a somewhat similar project with round tubing for a fancy job trailer rack.
He used CAD. As I recall it went something like:
Set a datum point for vertical, and centerline alignment and a zero station on the boat, trailer in his case.
Measure/Reference all mounting points on the craft to this framework, up and offset. Use a protractor or other precision tool to measure angles.
Set up the datum, alignment and then build the hard mounting surfaces in CAD.
Design your dream rack using the CAD tools. We had a welding utility plug in. Listed all the pipe cuts, bend locations and bevels, pretty cool. Allowed for strength testing too.
He measured, cut, bent and jig welded some. Some pieces he sent to automated machines.
You seem pretty do it yourself, but maybe someone down at a local CC would be willing to help draw it up, print a couple detail sheets, and even prepare a bar list. This was this students "with honors " project. I still see the local contractor using that rack. Makes me smile.
All grand ideas. I'm going to start by looking up the definition of "datum" and go from there 😂
 
Buy the boat you pictured with the tower you like.
It’s only money
I'd stick with the boat I have vs shelling out bunches of money. Buying a tower or having one built would be in the $5k ballpark. Neither options for me.
 
@Evan B - you continue to amaze me with your projects you take on. Just remember fishing comes before a new project...

Buy the roof you want and build the frame/tower to fit it?
 
@Evan B - you continue to amaze me with your projects you take on. Just remember fishing comes before a new project...

Buy the roof you want and build the frame/tower to fit it?
The roof is the easy part. I'm comfortable with fiberglass work as I've done a ton of that having rebuild an entire transom before.

This would be a winter project.
 
I didn't know there wasn't a Linux distribution. Now Im curious if you can get it to run.
I'm sure I could. But I may also explore any open source options that work on Linux as well. I'm sure there's several available that can do what I'd need. I have zero deadline to get this done, so when time allows am going to look into it.
 
There is something called FreeCAD. Its not very good compared to Fusion. SketchUp was a free Google tool at one point but now is offered by Trimble. There may be a free license.
 
Another thing that would help is the boat manufacturer may offer a CAD drawing for your boat. That would make the design build much easier. I'm not sure about boat builders, but lots of vendors offer simplified CAD for their stuff to assit with 3rd party builds.
 
One thing comes to mind is where your new attachment points are going to be, the backing and lamination build up for the new tower. Especially with a larger fiberglass top one would need to calculate not just static loading but more importantly the dynamic load applied. Such dynamic load would be considered for worst case, i.e. 70 mph with a 40 mph head and/or side wind.
 
One thing comes to mind is where your new attachment points are going to be, the backing and lamination build up for the new tower. Especially with a larger fiberglass top one would need to calculate not just static loading but more importantly the dynamic load applied. Such dynamic load would be considered for worst case, i.e. 70 mph with a 40 mph head and/or side wind.
Agreed. I was already planning on doing some fiberglass reinforcements if I install such a structure on it. I have lots and lots of fiberglass and resin laying around, so likely a combo of more glass and other reinforcing type things. Don't want to cause any cracking along the attachment points.
 
Terms you need to know:
Annealing
Mandrel bending
Cracking
Shot filled
Temp sticks
5052
6061
6063
5356
4043
Crater filling

I wouldn't get to hung up on CAD, unless your buddies tube bender is CNC. Also not all tubing benders are created equal. Bending aluminum tube is an art that is learned over time, and the best don't share their secrets freely.

It's definitely doable, but there is a learning curve, and you will scrap a bunch of aluminum.

Pro tip: hole saws work great for saddle cuts.
 
Timely... I just fished two days off the coast. Saturday was a quick evening sesh for salmon. My radar arch tower actually sheared, clean break, in one spot on the way in. Got to Home Depot right before close and pieces together a repair kit.
.
PVC inside, nice tight fit. Then found some square metal rods which we used as splints, held on with stainless hose clamps. Then covered those in gorilla tape just to make sure the vibrations don't wiggle that loose

20250720_105146.jpg1000009814.jpg
 
After careful considerations, I may purchase a heavy duty pre-fabbed arch. I may be ambitious, but I'm also a smoothbrain. Pipe bending may be beyond my potential. Additionally, the current tower beginning its descent from "flimsy and annoying" to "falling apart hazard" has made me realize I need to bump up my timeline.
 
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