Best Hardware for Trolling Motor Installation

[Sparky1423]

In Spring 2021 on my 2019 190 MONTAUK I will install a trolling motor using a quick disconnect bracket. The bow area of a 2019 MONTAUK has reinforcement from the factory.

Q1: what type of hardware is best to mount the trolling motor base to the bow of a 190 MONTAUK?

Q2: are stainless steel lag screws okay to use?

Q3: are anchors or plugs like "redheads" better [than stainless steel lag screws]?

I would like to avoid anchors if possible.

[jimh]

Q1: what type of hardware is best to mount the trolling motor base to the bow of a 190 MONTAUK?

A1: Stainless steel screw fasteners are best.

Q2: are stainless steel lag screws okay to use?

A2a: If the underlying reinforcement is wood, the appropriate screw fastener would be a wood screw. I don't understand your criterion "lag" for the screw. I would interpret that to mean a rather large diameter wood fastener often with a large raised square head. This type of fastener is not often used on boats in areas where the fastener head will be visible.

A2b: If the underlying reinforcement material is Whale-Board, you could drill and tap the Whale-Board and use machine screws.

A2c: I would expect that in some cases through-bolting may be preferred to just using screws into the reinforcement under the laminate to hold the trolling motor.

A2d: I suggest you inquire with Boston Whaler customer service and ask what sort of method of fastening the trolling motor to the bow is used when installed at the factory, then follow their example.

Q3: are anchors or plugs like "redheads" better [than stainless steel lag screws]?

I would like to avoid anchors if possible.

A3: I don't know what is meant by "redheads" and since you want to avoid them, they probably can be avoided.

[Sparky1423]

Thanks jimh for the great input. I finally reached out to the dealer yesterday and they also recommended tapping and threading into the phenolic material that reinforces the bow. I will be using stainless steel 5/16-inch x 18 thread machined screws to install the mounting hardware. That way in case of any severe damage to the trolling motor underway, I can reinstall with 3/8-inch fasteners in the future if needed.

[jimh]

SPARKY--your plan sounds good to me.

I do not know the exact composition of the internal reinforcement material used by Boston Whaler in the 190 MONTAUK, but I suspect it is probably a NEMA grade laminate. Here is a list of material properties of various laminates:

https://www.engineersedge.com/materials ... _13470.htm

I am familiar with G-9 (Melaime) which is often used as an insulated panel in electrical work. At 37,000-PSI tensile strength the material is quite strong. It is also known for its ability to be tapped for use with machine screw fasteners and to be very resistant to ingress of water.

[jimh]

Regarding using a “Redhead” anchor: the trade name REDHEAD is used by the company ITW REDHEAD for products used to anchor threaded fasteners into concrete. Since there is no concrete inside the hull of a Boston Whaler boat, using a REDHEAD concrete anchor would not be an appropriate method to anchor a fastener in a Boston Whaler boat.

Cf.: https://www.itwredhead.com/