Is this trolling motor setup safe?

[Xelaw]

My bowrider doesn't have a flat/level surface on the bow. Last week, I installed a mount for my Minn Kota Riptide SP (55 lb. thrust) using spacers and isolator bolts in 3 of the 4 holes on the bracket. The second time I used it, the nuts on the bottom of two of the isolator bolts came out of the holes that I drilled (hole size was correct) and the rubber at the neck of the Ts tore. I found out online that many people have had this issue with isolator bolts, even when mounting to flat surfaces.

I bought some Minn Kota quick nuts and remounted it. I shimmed it using rubber washers and nylon spacers. It feels like it's solid when I rock on it and apply pressure...there is a small amount of play between the flange and the first barb on one of the anchors. Do you guys think this will work? I'm chalking the first problem up to the isolator bolts, but I want to be safe. See the images below.

The image viewing area is not as wide as the pictures. There is a scrollbar at the bottom of the images you can move to view the right part of them.

Isolator bolts:

Quick nuts:

Front:

Starboard:

Port:

Top:

 

[fishrdan]

Re: Is this trolling motor setup safe?

Only 3 mounting bolts? You need at least 4. You'll need to drill the plate to get the 4th bolt installed somewhere on the starboard side. Are those quick nuts sitting at an angle into the holes in the hull, that doesn't seem too good. Honestly, it doesn't look like the TM plate is mounted very securely. I'm guessing there is no access to the inside of the hull so you can through bolt it.

With the mount secured and the trolling motor mounted and in the stowed position, have someone wiggle/jam the TM head up-down L>R and see how much play between the plate and hull. The boat bouncing over waves and the TM pulling the boat around will put a lot of leverage on the mounting hardware and loosen it up if it's not secure.

Also, once you are satisfied that the mount is secure and hardware going to work, seal up the holes in the hull with some marine sealer so water does not get into the hull. IE: take it back apart, put marine sealer on the quick nuts, then put it back together.

 

[Xelaw]

Re: Is this trolling motor setup safe?

I was going to seal it once I'm happy with the way it's mounted. The back two bolts have a couple mm play, but movement is restricted by the top flange and the first barb on the anchor inside the hull. The front bolt has no play. And you're right; I have no access to the underside of the hull to through bolt it.

I can add a fourth bolt to the starboard side, but it would be fairly close to the other one. See the image below for where I can drill the new hole (red circle). A bolt in this spot shouldn't have any play just like the other front bolt. Two bolts with no play and two with minimal play may secure it enough that the bracket can't move.

Will this work? Any other suggestions?

 

[Silvertip]

Re: Is this trolling motor setup safe?

Leverage from a trolling motor places a fair amount of stress on the mount so you really need to look at this mounting method some more. There should be NO movement on the plate. I've used the Well Nuts from Minnkota on three different boats, and one of my daughters and none of them have ever failed. The expansion plugs don't look very secure to me either. The spacers you are using are providing "point contact" to the hull and depending on how thick the surfaces are at that point may simply pull through. You need to make tapered blocks to spread out the load. My suggestion is to head to WalMart and buy a couple of the plastic cutting boards (or swipe the one from your kitchen). Cut as many layers as you need, then glue them together and shape them as needed. Drill the holes and then place them between the plate and the hull. As for the mounting, consider using toggle bolts. They require a larger hole to insert them but they will provide a stronger grip.

 

[Xelaw]

Re: Is this trolling motor setup safe?

Are toggle bolts safe to use with fiberglass?

 

[DJ]

Re: Is this trolling motor setup safe?

Are toggle bolts safe to use with fiberglass?

Nope. Anything mounted in "f-glass" should be "backed" with wood or metal.

 

[j_martin]

Re: Is this trolling motor setup safe?

Do the math.

1. Measure the distance between the closest 2 bolts in the mounting pad.
2. Measure (or guess) the distance between the prop and the mounting pad.
3. Multiply 55 times #2 divided by #1 and you have the force on the mounting bolts. I think you'll be pretty surprized.

Now, go bolt it down good and solid.

hope it helps
john

 

[Silvertip]

Re: Is this trolling motor setup safe?

Toggle bolts are just fine but my goodness -- we are supposed to be "creative" so if you insist on a the need for something for the toggle to bite on, consider that you CAN get a very large fender washer (or two if need be) through the 5/16 or 3/8 hole if you apply a little thought. You already have holes larger than that which you drilled for the well nuts. All you need to do is cut a slot the thickness of of the washer on each side of the hole. It need only be wide enough to get the washer through. The next question you have is how do I hold the washer? Think a little! A piece of wire formed with a "T" on the end will do nicely. Slip the washer over the wire. Pass it through the slots you made and pull the washer upward. Now what you say! Had you put an adhesive on the washer it would be secured to the bottom of the deck. But how do I get the toggle bolt through the small hole in the washer. Again, think a little! Had you made the hole bigger in the first place you wouldn't have to do it now. Heck, you could even cut a nice rubber washer from a bicycle inner tube and glue it to the washer to provide a little more cushion if you wish. Most problems are solved by logical thinking. Sometimes it doesn't work but it leads you to plan "B" which usually does. If you still decline use of toggle bolts, use the same procedure but size the hole in the fender washer for the well nuts like you previously used. Well nuts like a little thicker surface rather than thin which obviously tends to cut the rubber (as does over tightening the bolt). But use two washers to provide more thickness. Ahhh yes -- what to do with the wire? If you used a metal coat hanger you need only pull it out since it bends easily. Or an equally easy route to take would be to cut it off short and let it drop into the hull. Unless there is a critter inside nobody will see it.

 

[Xelaw]

Re: Is this trolling motor setup safe?

Thanks silvertip, that's a great way for me to get the bracket mounted snugly.

Now let's back up a bit. If I get all of the bolts completely snug and add a fourth hole in the area I was talking about in my previous post, will that be enough to secure the trolling motor? It'll only be supported at four posts, and the two bolts on the starboard side are going to be pretty close together?

Is this worth trying, or should I go for the cutting board idea? I was thinking of scribing the bow shape onto cardboard to use as a pattern for the cutting boards. Would this be the best way, or is there an easier way?

 

[Silvertip]

Re: Is this trolling motor setup safe?

It's all about surface area when it comes to mounting something that presents a lot of leverage. Keep in mind that the plate does not need to point straight forward. It can be turned to the side a little more. Can't tell from the picture but it would appear the left side bolts are lined up toward the center of the bow -- am I correct?? If so, why not turn the plate clockwise a bit which would provide a little more boat to work with.. The motor does not need to be centered on the bow.

 

[fishrdan]

Re: Is this trolling motor setup safe?

The motor does not need to be centered on the bow.

Very good point ST. With the way the plate is mounted now the head of the TM will be poking straight back into the bow area, where it should be pointing towards the gunnel to get it out of the way.

Xelax, check out some bow mount trolling motors mounted on boats, fishing boat's etc. The motor drops over one side of the boat (starboard) and the when stowed the head of the TM goes to the other side of the boat (port). Something like...

 

[Xelaw]

Re: Is this trolling motor setup safe?

I spent a while playing with possible positions before drilling. Between the navigation light and a steep lip around the inside rim of the deck (see the port picture), this was my best choice. The shape of the deck makes this quite a pain. When I installed this on my previous boat, which was also a bowrider, I didn't have any problem whatsoever.

Guess I'm going to go ahead and try to make a brace out of cutting boards and see how that works. Any more suggestions for what I can shim it with would still be appreciated.

 

[Silvertip]

Re: Is this trolling motor setup safe?

Brace is not the word to use here nor is a cutting board material suitable for "bracing". Shim is what you are after. To shim is to create a spacer shaped to a contour of two surfaces that replaces the washers you used. The shim spans the two bolts at each side of the plate. The shims take into account the contours (flat on top for the plate, and contoured on the bottom to match the hull lines), plus they allow you to level the plate and lessen the point contact issue described previously. MinnKota makes a longer version of the plate you are using. Using the longer plate would allow the inboard end of the plate to be secured to the deck while the outboard end could still be fastened to the hull thus spreading out the loading and lessening the leverage effect. Again, cutting board material can be used as spacers or shims. I only suggest the cutting board material because it is tough stuff and is not subject to rot and decay. Similar material is available at marine stores under a number of trade names but is more expensive.

But I really think you can turn the plate a bit more clockwise rather than pointing it as far forward as you have it. The picture above is a great example of how it should be installed.

 

[Xelaw]

Re: Is this trolling motor setup safe?

I took my boat to a couple of places that to TM installations. After fiddling with the bracket position, both said that I really shouldn't be mounting a trolling motor on the bow because of how little space it has. Rather than deal with this anymore, I think I'll sell my trolling motor and buy a transom mount motor. I know it won't handle as well as a bow mount, but at least I'll have something. It's not exactly a fishing boat anyway.

 

[Silvertip]

Re: Is this trolling motor setup safe?

You give up way to easily. I've never seen a boat, bow rider or not that you cannot mount a troller on. If you provided a more inclusive picture of the bow of your boat we can probably offer workable solutions.

 

[fishrdan]

Re: Is this trolling motor setup safe?

I took my boat to a couple of places that to TM installations. After fiddling with the bracket position, both said that I really shouldn't be mounting a trolling motor on the bow because of how little space it has.

Wrong, they just didn't want to put in the time to fab up a bracket, didn't have the skills or,,, didn't want to have you pass out once you saw the estimate to mount it... (I had a bow TM on my old tri-hull and had far less surface area to work with, than your boat)

Honestly, I think the best solution would be to make up a custom fiberglass wedge that would conform to the bow and have a flat top to mount the TM. Tape up the bow, box in a form, then start fiberglassing the sides and bottom. Once those are sufficiently thick, level off the top and fiberglass on a top plate (plywood, cutting board, etc). Cut a hole in the top so you can access the bolt holes for the hull and screw it down. Drill your plate mounting holes, install a couple T-nuts in the holes and screw the plate down. It's not a quick and easy install, but would certainly be strong enough for the TM.

BTW, I have a bow and transom mount on my 18'er. The bow mount works well for precision positioning, but sucks for long distance running (trolling). The transom mount works great for long distance running (trolling) but sucks for precision positioning. I really depends on what you are going to use the TM for, as whether you want a bow mount of transom mount.

 

[Xelaw]

Re: Is this trolling motor setup safe?

There is a Bass Pro service center near me, I imagine they deal with trolling motors frequently. I'm going to give them a call and see if they think they can handle it. If I come up with a good way, I'll still do it myself. Unfortunately, I don't have any fiberglassing experience and I'm not sure that I want to learn on my new boat.

From what I've seen, people have had success flipping their trolling motors and mounting them to the swim deck. I think it would be a much easier and safer option for me.

I suppose I am giving up easily, but I've already drilled into my deck once and don't want to do it again. I also want to spend my spare time using the trolling motor, not installing it. (And I want something that works before speck season is over).

Since this isn't really a fishing boat and the hull is deep, I won't really be trolling in spots where I need a high amount of maneuverability. I just want to be able to troll down the middle of the river or in a straight-ish line on a lake or in the flats.

I'll post some pictures covering more of the bow soon, I can't take very good pictures now since it's night.

 

[Xelaw]

Re: Is this trolling motor setup safe?

Here are more bow pics:

 

[Silvertip]

Re: Is this trolling motor setup safe?

Just as I thought. You have plenty of room and all it takes is the "spacer" I suggested and a little imagination. The first picture is the MinnKota "long mount". It is the same as the standard mount but is longer.

In this picture I show the outline of that mount positioned on your boat. Note that it is mounted above the Nav light and on the starboard side of the boat. Most trollers are mounted so when stowed, the shaft sits above the "port" side gunnel. But I showed it on the same side you used previously since that's where the existing holes were. Since I don't have the boat and plate dimensions, the perspective may be off a bit and the area in the lower left corner of the plate may overhang the seat backrest more or less than shown. That overhang is not an issue and can be cut off and edges rounded with a file and covered with any type of padding or even a piece of rubber hose that has been slit and glued to the edge for protection of bar skin. Again, two spacers is all it takes to space the plate above the Nav light. Make a spacer template using cardboard. The spacer will need to be thicker at the tip of the bow to compensate for the slight downward rake of the bow. This is not rocket science -- it just requires a little thought. Tape a two-layer piece of cardboard on top of the nav light. Set the plate on the light and orient it so that when the motor is installed and stowed, the shaft will follow the general path of the gunnel. You don't want the shaft pointing down the middle of the boat as it takes up walk around and seating space. When you have the plate positiioned, place a piece of cardboard vertically along side the plate. Lay a marker sideways on the bow and drag it along the contour of the bow so it leaves a line on the cardboard. The resulting line on the cardboard establishes the contour of the bow. Remove the cardboard and carefully cut it on the line you made. Now place the cardboard back on the bow to fine-tune the cut if necessary. When satisfied with the contour, place the cardboard vertically again and mark another line that follows the bottom of the plate from end to end. Cut the cardboard on that line. You now have a template for that side of the plate. Repeat the process for the other side. You can make the spacer by tracing the pattern using the template. Properly stained and varnished hardwood like oak or maple is cheap, easy to cut and sand, and if you screw up, you can make another in a few minutes. The longer you make the spacers the more support you provide. For assembly, you drill new holes in the plate wherever necessary. They should always be as far forward and as far back as possible.. You will likely need to buy longer stainless bolts.

 

[Xelaw]

Re: Is this trolling motor setup safe?

Thanks again. I'll take a look at this tonight and see how it works. I'll also put up some pics with a ruler across for better measurement. Couple questions:

Why do you recommend the long mount?

I have some spider cracks from when the trolling motor shifted out of position when I was using the isolators. Should I get these fixed first before doing anything else? I don't want to make them worse.