23se trolling motor mounting

[Fishaddict]

Will be by my boat in 8 daysto take pictures. Bracket is made out of HDPE king board like material and has zero adherence to epoxy other than mechanical bond. Bow cap is cored up to last couple of inches to the tip. Was lucky not needing to move navigation lights because I have 2 separate lights at the bow. Boat is 2003 but customized for NC Wildlife. My next big undertaking is a 6 hp kicker on bracket on transom.

 

[rseate]

Salty - thanks for the info.

Rseate, did you use Rhodan's mounting aluminum plate? Was it necessary or could you have mounted the TM directly on the cap? Have you had the boat out yet? Curious to see how that battery size works for you...

No, I picked my plate up locally and drilled / countersunk the screw holes myself. I could have mounted it directly to the deck with the puck but chose not to. I wanted to spread the load on the deck out over a larger area and not have high point loads by just using the puck. Using just the puck, all of the force is placed on just the area where the four mounting screws go through the deck. By using the plate (and I put 4200 under the plate when I mounted it) most of the force is spread out over 144 sq inches.
I have not had the boat out yet, it’s our marlin tournament season so that’s where I’ll be spending most of my fishing time through June. My son in law took it out and said everything worked great. He was in about 2.5 footers at 6 seconds with 10 knot winds. He said he had it in the water for about 5 hours on spot lock and had about 35% battery life left when he came in.

 

[Key Largo]

When I installed mine my deck was cored. Once I drilled all of the holes I coated the "grain" of the wood with a thin layer of epoxy and allowed it to dry. Before I put the aluminum mounting plate down on the deck I put 4200 under it to help with spreading the load out.

Your trolling motor is a 84 inch shaft on the 23DVCC ??

 

[rseate]

Your trolling motor is a 84 inch shaft on the 23DVCC ??

Yes

 

[Key Largo]

Thank you. I am planning on getting one in the fall when I fish the patch reefs in 2.5 ft seas and thought the 84 inch shaft was the proper length.

 

[sydngoose]

You don’t need a backing plate for bow mount on Parkers IMO. Just use oversized SS washers and locknuts.

When drilling through deck surface or bow cap the proper sequence would be to over drill each hole, put tape under each, and fill with epoxy- not 4200. Let dry 24hrs and then re-drill with appropriate sized drill bit. This way you have a cuff of epoxy protecting your cored bow cap and a snug fit for your through bolt. Squirting silicone or 4200 in the hole is suboptimal.

Every bow mounted TM needs a backing plate. Period. I have seen and read others' installations that literally ripped the forward casting deck out. The torque on these things is insane.

 

[MartyL]

Got the new hatch cut in. Looks lhe entire bow cap is cored over the anchor locker. Looks like the raised portion, where the nav light and cleat are, is twice as thick as the non-raised. After seeing the entire inside of the bow area, on my boat there is no way that you can mount a trolling motor and backing plate anywhere near the centerline of the boat without having additional access from the factory anchor door. Now to seal up what I've cut and drilled... Trolling motor in 2 weeks

 

[rseate]

Got the new hatch cut in. Looks lhe entire bow cap is cored over the anchor locker. Looks like the raised portion, where the nav light and cleat are, is twice as thick as the non-raised. After seeing the entire inside of the bow area, on my boat there is no way that you can mount a trolling motor and backing plate anywhere near the centerline of the boat without having additional access from the factory anchor door. Now to seal up what I've cut and drilled... Trolling motor in 2 weeks

You're correct, that raised area is thick, I had to use 4" bolts when I mounted mine for the bolts that went through the puck.

 

[pelagic2530]

Got the new hatch cut in. Looks lhe entire bow cap is cored over the anchor locker. Looks like the raised portion, where the nav light and cleat are, is twice as thick as the non-raised. After seeing the entire inside of the bow area, on my boat there is no way that you can mount a trolling motor and backing plate anywhere near the centerline of the boat without having additional access from the factory anchor door. Now to seal up what I've cut and drilled... Trolling motor in 2 weeks

View attachment 29110

Looks great!

 

[Fishaddict]

"Every bow mounted TM needs a backing plate. Period. I have seen and read others' installations that literally ripped the forward casting deck out. The torque on these things is insane."

1801 has large area of 3/4 ply glassed in bow. I used 1 1/2 '' fender washers in 5 out of 6 holes. Do you think this is enough without backing plate?

 

[MartyL]

Looks great!

Thanks to your help...

 

[MartyL]

"Every bow mounted TM needs a backing plate. Period. I have seen and read others' installations that literally ripped the forward casting deck out. The torque on these things is insane."

1801 has large area of 3/4 ply glassed in bow. I used 1 1/2 '' fender washers in 5 out of 6 holes. Do you think this is enough without backing plate?

Looks like I have 11/2" of glassed marine plywood where I am going to mount my trolling motor, I plan on using a backing plate, probably 1/4" G10 on the inside. I'm undecided if I will do anything on the outside but some have used an aluminum plate under the TM to mount the motor. I don't know if it is really necessary but I figure it's cheap insurance...

 

[Fishaddict]

Looks like I have like 11/2" of glassed marine plywood where I am going to mount my trolling motor, I plan on using a baking plate, probably 1/4" G10 on the inside. I'm undecided if I will do anything on the outside but some have used an aluminum plate under the TM to mount the motor. I don't know if it is really necessary but I figure it's cheap insurance...

Are you putting backing plate on underside surface of the bow? I think the chance of plate to be perfectly flush with glassed surface is close to none. Your plate than will be pressed against 3 small surface areas and other bolts will have a gap between a plate an glass surface. Might be bedding it in epoxy peanut butter before drilling holes would fix the issue. I also mast say it was close to a quarter of an inch of glass on the top of plywood. As to force TM exert on mounted surface it depends on how close is shaft to bow edge and if you are using full thrust of TM.

 

[MartyL]

This article provides interesting info.

https://www.boatus.com/expert-advic...eptember/the-critical-world-of-backing-plates

 

[rseate]

This article provides interesting info.

https://www.boatus.com/expert-advic...eptember/the-critical-world-of-backing-plates

This article goes back to the point I made in an earlier post in this thread. By using a backing plate (and a deck plate) you are spreading the forces of the trolling motor over a larger area. Point loads are killers and that what results from trolling motor mounts bolted directly to decks.

 

[MartyL]

This article goes back to the point I made in an earlier post in this thread. By using a backing plate (and a deck plate) you are spreading the forces of the trolling motor over a larger area. Point loads are killers and that what results from trolling motor mounts bolted directly to decks.

I don't know if I'm not understanding something here. Are 'point loads' caused by uneven surfaces or something else. If it's an uneven surface that will be true if you have a deck plate or backing plate or both? Why would it be an issue only when you bolt the TM directly to the deck?

 

[Andy]

This article provides interesting info.

https://www.boatus.com/expert-advic...eptember/the-critical-world-of-backing-plates

Hi MartyL, thank you for posting this; it's a great reminder of backing-plate 'good-practices'....
The picture of Balsa Core, caught my attention, and brought back nightmares of decades of boat repairs...
Here's a side-note; Whoever it was who invented 'Balsa Core', and then decided it would be a suitable material to use in boats, I hope he (she?) is down 'there' roasting marshmallows with Satan!....(sorry, that's a bit strong; I wouldn't wish that, on the marshmallows).
When Balsa Core was first introduced to the marine market, we were all assured that it was a great product, light weight and strong, and that it was IMPOSSIBLE for water-intrusion to wick-its-way longitudinally, through the product.... I doubt if there has ever been a more incorrect assessment of any boat-building product... Balsa Core has got to be in the Top Ten if worst ideas/products ever used in boat construction....
Sorry for the rant, but anytime I hear "Balsa Core" my blood boils! ☺....
And yes, there have been boat builders, that even used Balsa Core in the hulls....

 

[Fishaddict]

Backing plate if your goal is to spread the load needs to be bedded. Otherwise it will not work. It is no different than putting house on uneven foundation.

 

[MartyL]

Backing plate if your goal is to spread the load needs to be bedded. Otherwise it will not work. It is no different than putting house on uneven foundation.

I understand that as it applies to uneven surfaces and that the undersides are most likely to be uneven. What I was asking was if it applies to a backing plate shouldn't it also apply when mountig a TM puck or any type bracket directly to the cap on the outside?

 

[rseate]

I don't know if I'm not understanding something here. Are 'point loads' caused by uneven surfaces or something else. If it's an uneven surface that will be true if you have a deck plate or backing plate or both? Why would it be an issue only when you bolt the TM directly to the deck?

We deal with this almost daily in the buildings that we design & build. Imagine that your trolling motor shaft is down and you applied a constant load on it from the front of the shaft toward the rear of your boat. The force would attempt to pull the four mounting bolts up through your deck (your rear two bolts would actually receive the bulk of the force). The force would be concentrated on those four specific points of contact where the washers were located under the deck. When you have a backing plate, and also a deck plate should you choose, those same forces would now have to pull the entire plate through the deck thus the load is spread out over a wider area.