Topic: The infamous where to mount the SI transducer! (With pics)

[Rotus623]

Sorry for even asking guys but I am new to this. I saw a link to lots of aluminum boats but none had quite the look of mine. Where would you guys put the ducer?

[Rotus623]

[LocDown]

I would probably put it just to the left side of the right bunk. You could get a transducer mounting board and glue it so you don't put any holes into the boat. If you do go that route, you could also probably file the mounting board down some to go over those 4 rivets. Just my opinion.

[Rotus623]

Are people gluing ducer boards on these days? And you know what's funny all of those rivets down there are old transducer holes. I put rivets in them before I painted the hull.

[LocDown]

People that don't want multiple holes while trying to find the sweet spot for the transducer.

[strawdg]

Actually..... it is hard to tell much without the outboard installed....

But it looks like a nice hull without a bunch of things to cause problems with disturbance .....

Do you want on plane readings.....?

Installing a Jack Plate...... ?

Oh BTW Really great looking boat.....

[Rotus623]

Thanks straw! I just painted her. The motor is an '84 evinrude 75hp with powertrim, so I think that aspect will be fine

[Rotus623]

On plane readings would be great but I've never been able to get them.

[strawdg]

Thanks straw! I just painted her. The motor is an '84 evinrude 75hp with powertrim, so I think that aspect will be fine

Yep.... trim'er' up when needed.....

Hmmmmm did I say..... wow fantastic boat....

Straw

[Rotus623]

Thanks buddy. If you get bored check out this thread. It shows this boat when i got it until right now. Loooonnng expensive process..... http://forums.iboats.com/boat-restoration-building-hull-repair/86-aluminum-starcraft-restoration-589808-9.html

[rnvinc]

You can also mount the Xducer to a board (or similar) and C-clamp it to the transom for testing different spots for "clean bubble free" water...

Rickie

[Humminbird_Greg]

I would probably put it just to the left side of the right bunk. You could get a transducer mounting board and glue it so you don't put any holes into the boat. If you do go that route, you could also probably file the mounting board down some to go over those 4 rivets. Just my opinion.

I would think that you would get better possible high-speed depth readings with the transducer mounted in the area with only two rivets (green oval) as opposed to the four rivet area (red oval).  Farther down in the water and closer to the motor is generally the best location.

[Rotus623]

Sounds good to me Greg. If it is that low I'm sure I won't have SI interference with the keel either. Ifs be sweet if those old rivets lined up with the holes in the new ducer too but that's wishful thinking. What do you guys think about a small piece of solid PVC trim for lowes as a mounting board?

[h8go4s]

I used a piece of composite deck board. Drilled & counterbored holes to mount it to the transom, spot-faced the back side for rivet clearance and put two coats of black paint on it. Seal the transom holes and the edge when you install it and it's good for years. You probably could use cedar or redwood to, but I'd paint it good first.

[Rotus623]

I like the composite deck board idea. I have thought about that, just wish that stuff came in smaller pieces. I also toyed around with PVC trim, although I doubt that would hold up as well. I wish I could have the best of both worlds. Im not overly excited about having a big ugly board hanging off the transom....

[raypla]

I picked up a 1'x1'x3/4" piece of gray pvc sheet for $12 then $9 s+h, cost me $21 to my door, it's UV stable and paintable.  They have standard white stuff to.  I plan on cutting it right on the table saw.  I picked it up here http://freckleface.com/shopsite_sc/store/html/plasticmaterial.html

 

[Rotus623]

Ok guys what you think for mounting position now thy you have the whole picture?

[Rotus623]

Same spot?  Green circle?

[Rotus623]

So I have 3holes that line up perfectly to mount the ducer but will the deadrise angle be an issue?
you can see where the cluster of rivets are.

[Humminbird_Greg]

Same spot?  Green circle?

Same spot, Green circle (the spot with only the two rivets).

[Rotus623]

Ok thanks Greg. I just bought a 4" wide 3/4" thick 8foot long strip of rot free PVC trim to make a mounting board out of. $13 from lowes. I was thinking about putting a piece from about center of the keel all the way past the red circle that way I will have a nice span to choose from while moving this thing around. And then worst case scenario I can unscrew the board and use it as a template for the fresh piece so it doesn't have holes all over it. Also it leaves me the ability to add an extra ducer if need be. Ill get some photos when I'm done. Thanks again!

[Rotus623]

Here's what I came up with guys. Ill let ya know how she does in a week or so when I get on the water.  
Trimmed up.

[Rotus623]

Trimmed down.

[Rotus623]

Here's the full picture.

[backlashed]

Nice restoration!
 I have the 18 foot version of the same boat. I mounted my transducer in approximately the same place as where you have the 3 rivets together at. I get good SI reading at low speeds, and have good depth reading up to about 20 MPH.
There is always room for improvement, so I'm anxious to hear how your does where you have it mounted.   


BTW, here's a link to my restoration pictures. I sure like them old Starcrafts. A lot of newer boats still use the same hull design.
http://s163.photobucket.com/user/backlash_1/library/Starcraft%20Restoration?sort=3&page=1

[Rotus623]

Wow good for you lash! That boat looks great! I think I'm going out this weekend so ill record some runs so you can pop em up on humviewer. Greg seemed pretty confident about this location so I'm sure it's going to work great!

[Rotus623]

Well fellas finally got the boat in the water for some testing. Boat does 34MPH. SI and DI images look amazing. There is no interference from the skeg, oddly not even when trimmed down. I do get a little prop turbulence when trimmed down, however. But nothing a little trim raise can't handle. So good call on the location for that application. There is barely any rooster tailing at all, and amazingly, I get accurate bottom readings all the up to 34 MPH!! That is just amazing to me. Greg you really hit the nail on the head with this one. I was absolutely amazed with the quality of my images, and feel very fortunate to have nailed it on the first mounting location!!  Thanks for all guys. Ill post some vids and pics once I get humviewer figured out.

[Humminbird_Greg]

This doesn’t happen that often guys.
Rotus you must have been working on your luck as I haven’t had much of the good type lately. 

[Rotus623]

Thanks Greg!! Sorry about your luck bud. You darn sure know your stuff though. And trust me, I have had my fair share of bad luck. I was amazed that I got it right the first time. Still cant believe it!