Transducer install....adding King Starboard to transom

[SoCalAngler]

Hello all--

Getting ready to install my new Lowrance HDS-7 Carbon with Total Scan transducer!!!  I had the HDS-9 on my last boat and it is a great unit.  The Carbon adds a few nice features like Solar-Max HD  screen and a faster processor.

Mounting transducer calls for typical starboard side of lower transom... a few inches to the right of prop diameter (for right hand rotation props).

Since I'm not a fan of drilling directly into transom (previous owner did drill a few holes on port side and starboard sides (of motor) of lower ransom area....I believe I will add King Starboard material to both sides of transom.  Thinking of a 3/4" thick by 4"x10" block to transom, on each side of motor, will cover existing holes as well as provide a location for transducer mounting on starboard side and bait pump on port side.

NOTE:  I will attach King Starboard material with West System epoxy. 

Thoughts?

[croaker stroker]

Epoxy will not bond to Starboard.

http://www.smithmountainstriperclub.com/the-boathouse/making-a-transducer-mounting-plate

[DevMah]

Hello all--

Getting ready to install my new Lowrance HDS-7 Carbon with Total Scan transducer!!!  I had the HDS-9 on my last boat and it is a great unit.  The Carbon adds a few nice features like Solar-Max HD  screen and a faster processor.

Mounting transducer calls for typical starboard side of lower transom... a few inches to the right of prop diameter (for right hand rotation props).

Since I'm not a fan of drilling directly into transom (previous owner did drill a few holes on port side and starboard sides (of motor) of lower ransom area....I believe I will add King Starboard material to both sides of transom.  Thinking of a 3/4" thick by 4"x10" block to transom, on each side of motor, will cover existing holes as well as provide a location for transducer mounting on starboard side and bait pump on port side.

NOTE:  I will attach King Starboard material with West System epoxy. 

Thoughts?

5300 or silicone with 2 to 4 screws into the transom, nothing will bond fibreglass to starboard.

Dev

[SoCalAngler]

I believe the G/Flex, and alcohol/flame treatment are the best option.....

https://www.westsystem.com/specialty-epoxies/gflex-epoxy-adhesion-data/

NOTE:  I've used West System on my last two alum boats with great results....both used starboard....one with G/Flex and flame treatment and one with 105 resin no flame....both adhered excellent.  I did drill several holes 1/2 way through material on both applications but did not dovetail.

[SoCalAngler]

Epoxy will not bond to Starboard.

http://www.smithmountainstriperclub.com/the-boathouse/making-a-transducer-mounting-plate

Thanks for the link Mark.

1.  Can you determine what the two small holes are for near the right and left ends of the starboard?  Appears they may have been for screws, but I don't see any screws????

2. One of the comments suggest using a tap, loctite, and finger nail polish.....I understand the tap....what is the reference for the other two?

3.  How would one tap threads that are very coarse to assist in the mechanical advantage of adhesion?

Thanks

[sfever]

No expert but think to be safe you gotta drill into the transom and not rely on any adhesive to make sure that it stays on. Many, many boats have holes in the transom for trim tabs or transducers so just use good sealer for the holes and mount. I had some holes in the transom and looked at buying the gel coat repair kit and instead just hired a boat repair guy for $100 to come down and match the hull color repair so it's hard to see where the holes where.

[Fisherdv]

Are you planning to install trim tabs? Plan very carefully before you glue anything to the transom. There is not much room back there. I used a Stern Pad for my transducer. Works well. They also have a jumbo size for the larger transducers.

https://www.amazon.com/Stern-Pad-Screwless-Transducer-Transducers/dp/B06XFKBTY1/ref=sr_1_9?crid=2JSGV23ZS855U&keywords=stern+saver&qid=1560310113&s=gateway&sprefix=Stern+%2Caps%2C231&sr=8-9

[Fisherdv]

Here's the jumbo size stern pad for the larger transducers. No drilling, no messy glue. Just peel and stick.

https://www.amazon.com/Stern-Pad-Jumbo-White-Transducers/dp/B079DWDDWC/ref=pd_cp_107_1?pd_rd_w=gAaTx&pf_rd_p=ef4dc990-a9ca-4945-ae0b-f8d549198ed6&pf_rd_r=443NAM63PG5D1Z3Y24QE&pd_rd_r=1396a91d-8cc4-11e9-9cfe-ef4eaf4a271b&pd_rd_wg=HxVAe&pd_rd_i=B079DWDDWC&psc=1&refRID=443NAM63PG5D1Z3Y24QE

[Fishgriller]

Are you planning to install trim tabs? Plan very carefully before you glue anything to the transom. There is not much room back there. I used a Stern Pad for my transducer. Works well. They also have a jumbo size for the larger transducers.

https://www.amazon.com/Stern-Pad-Screwless-Transducer-Transducers/dp/B06XFKBTY1/ref=sr_1_9?crid=2JSGV23ZS855U&keywords=stern+saver&qid=1560310113&s=gateway&sprefix=Stern+%2Caps%2C231&sr=8-9

I used this pad to mount my transducer when I did the trim pads several months ago.  So far seems like quite sturdy.  Since the installation, I've taken the boat to 40mph, the pad and transducer have not budged.

[AJFishin]

Are you planning to install trim tabs? Plan very carefully before you glue anything to the transom. There is not much room back there. I used a Stern Pad for my transducer. Works well. They also have a jumbo size for the larger transducers.

https://www.amazon.com/Stern-Pad-Screwless-Transducer-Transducers/dp/B06XFKBTY1/ref=sr_1_9?crid=2JSGV23ZS855U&keywords=stern+saver&qid=1560310113&s=gateway&sprefix=Stern+%2Caps%2C231&sr=8-9

X2 on what Fisher said.

I bought a pice of starboard off of Amazon, cut it in half, used 1 screw with boat life life seal in the hole and around the piece, holds well.

https://www.amazon.com/dp/B00H0FO82Y/ref=cm_sw_r_cp_apa_i_yooaDb2059CAD

This is a picture with my old Humminbird transducer, but now I have a larger Garmin transducer on the same starboard piece.

[SoCalAngler]

Thanks for the links on the stern saver....I have seen the Stern Mate and Stern Saver (both use a glue/epoxy) but never these that use the 3M double stick tape.  I wonder if that tape can be purchased separately and be used with my own custom size starboard material?

I was not planning on trim tabs.....does the boat not perform well without them?
I have a Honda 50hp 4 stroke and fish with just two aboard.

[croaker stroker]

I have purchased the 3m VHB tape on Amazon and at Home depot.

...or you could make the mushroom shaped holes in the Starboard as shown in the link I posted, and use 5200 for attachment rather than a bond.

[SoCalAngler]

Thanks for all of the replies.  Going to rethink the install before I move forward.  All the info provided is great and gives me a few options.  Going to take boat out today.  I'll mark water line and also see how she rides without trim tabs.  She's never had them, so it may ride fine without them. 

[SoCalAngler]

I've notice many here mount their transducer on port side of motor.  Most manufacturer's recommend starboard side of motor on RH rotation props...so water disturbance if pushed down instead up up into transducer (port side mount).....

Why the port side mounting?

[DevMah]

I've notice many here mount their transducer on port side of motor.  Most manufacturer's recommend starboard side of motor on RH rotation props...so water disturbance if pushed down instead up up into transducer (port side mount).....

Why the port side mounting?

You are correct that depending on the rotation of the prop the water should be pushed down into the transducer, some of us have more than one transducer and with trim tabs the available space is limited.


Dev

[SoCalAngler]

I have purchased the 3m VHB tape on Amazon and at Home depot.

...or you could make the mushroom shaped holes in the Starboard as shown in the link I posted, and use 5200 for attachment rather than a bond.

A few questions.........

How well will 5200 adhere to Starboard?

A little research indicates 3M VHB tape will not adhere to polyethylene....thoughts?

I wonder if that kit uses King Starboard (HDPE)?

Now I'm confused as to what to use.....still sticking to my no holes drilled

Decisions, decisions, decisions.....

Thanks!

[croaker stroker]

It doesn't adhere at all. The back-cut mushroom shaped hole forms a mechanical fastening "plug".

Personally, I just drill holes and screw my transducer directly to the transom. If I need to move it, I just patch the holes.

[Fisherdv]

If you want to go the screwless route you have 2 options, Stern Saver or Stern Pad. One uses epoxy with the "mushroom threads" that CS mentions, the other uses the peel and stick VHB tape. Look them both up to see how each one works. I have used both, but I prefer the Stern Pad with the tape.

[Arimadrifter]

What Croaker said. Nothing will stick well to starboard but many adhesives will stick great to Figerglass. The "mushroom" holes in the starboard are the key to having it "hold" the starboard in place.

[Packman]

I used 1" starboard, 4" x 12".  I used previously drilled (and filled) holes to attach the starboard to the transom, first adding silicon sealer to the holes and around the perimeter of the starboard.  That way I didn't have to drill new holes in the transom and the starboard is firmly held in place.

[AlexB]

I used 1" starboard, 4" x 12".  I used previously drilled (and filled) holes to attach the starboard to the transom, first adding silicon sealer to the holes and around the perimeter of the starboard.  That way I didn't have to drill new holes in the transom and the starboard is firmly held in place.

Seems like a great idea. If the OP is trying to fill/cover existing holes anyway, why not fill them with screws and sealer while simultaneously adding a chunk of starboard for attaching the transducer?

Use some tracing paper to make a template and go for it!


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[Koopa253]

IMO - The Stern Saver with 3M backing is the only way to. It doesn't break the bank, is very easy to install, and stays on like it's bolted. I'm going on 5 years with a Airmar TM-150 with zero issues. These are perfect for fiberglass boats and are a quality product.