Modifying a Tracker V12 – Fastener Selection

Hi there I’m very new to this boating thing and this forum.

I recently purchased a Tracker 12 and I want to add a sole, remote throttle and rotary steering. The sole and console will be fabricated from marine ply that’s sealed with epoxy.

The sole will be a snug fit and will be kept in place with two cross members fastened to the bench seats. (see image)

http://img147.imageshack.us/my.php?image=constructionsketchtr9.jpg

My real concern is the type of screw that should be used. The aluminum is quite thin and I understand that if the wrong fasteners are used the galvanic effect can corrode the boat.

Any input would be greatly appreciated

PS: any comments on the planned mod are also welcome

 

Here's a little more detail on the plan:

http://img359.imageshack.us/my.php?image=sideplanviewstc0.jpg

But as I mentioned earlier I'm concerned about screws anybody willing to help me?

Here's my shopping list:

Steering system
http://boatstoreusa.com/productdeta...37_steering_system_(With_Wheel)&ProductID=780

REMOTE CONTROL CONVERSION KIT 0775982
REMOTE CONTROL, SIDE MOUNT, KEY SWITCH 0177224
REMOTE CONTROL SINGLE LEVER CONTROL 0174229
SHIFT THROTTLE CABLES (SNAP IN) 0173105

 

Well I found these:

http://www.aluminumfastener.com/productsmain20.htm

You guys aren't very talkative ....

One more question:

Do I need to glass the sole if it's made with marine ply? Or will a marine pat be good enough?

 

adding to a thin aluminum skiff

blindlove,

First, I'm more experienced in welded aluminum not thinner riveted boats so I may not be very helpful, but as no one else seems inclined to reply- I'll give it a shot.

I'd rivet the points on the two transverse deck/cockpit sole supports and make the supports out of aluminum angle (6061 T-6) because this would be an all metal solution.

If the two cross hull supports are 2x4's or wood (?) then screws might be OK if they're installed from inside the bench seat- otherwise I'd rivet the transverse supports regardless of what they're made from.

Screws into the bench seats are a short term solution, as the metal around the screw holes gets only slightly (0.001") elongated the screw grip goes away and the hole wallows out and you can't refasten without larger diameter screws. However, if the screw were in the metal from the inside the bench and then threaded into the wood sole support (?) they're OK: not the best, but surely better than if you tried to fasten into the folded bench seat wall.

I'd say any seat wall thinner than 0.125"-1/8" wouldn't hold screws well, below that I'd rivet and from 1/8" thicker screws might work. Generally thread in aluminum are poor practice unless they're tapped, screws would form there own and that means they'd give up much more quickly under a load.

Any SS screw with Tef-Gel or white pipe thread paste as a bedding will work well enough for your application of SS screws into aluminum, unless there will be constant bilge water (?) then- aluminum rivets make a more reliable choice, again.

aluminum fasteners are not good practice as they're soft and weak compared to SS, even if they're 'aluminum' they seem to loose their drive slots or recesses too easily, I'd stick with aluminum rivets or SS screws from the inside out, depending on seat thickness?

Better than glassing plywood, marine or otherwise, is to soak in thinned epoxy then coating in several layers of heavier, thicker epoxy and finally using sand in the final layer to create a traction surface that is compatible with the other coatings. Epoxy is water vapor proof and polyester resin is not vapor proof so the epoxy works better to encapsulate wood or plywood.

hope this helps?

cheers,
kmorin

 

WOW ... thanks for the info

 

Unfortunately the hull and seats are only 0.080 5052 marine Alloy.

The depth of the seats will make it almost impossible to place a screw or bolt through the seat from the interior of the seat. So I was considering three long bolts (a bit extreme granted) going right thru both surfaces of the seat then into the wooden member that holds the sole down.

See pic.
http://img291.imageshack.us/my.php?image=bigboltsvz3.jpg

so where can I get 18" bolts?

 

If I want to rivet aluminum angle to the bench seats will aluminum 3/16" pop rivets be adequate. The sole will really rest on the chines and the sole is then screwed to the aluminum angle so it stays put.

 

rivets and angles for cockpit sole

blindlove,

yes that is fine, 3/16" rivets are OK, but I'd tend to use two rows staggered vertically and horizontally 1" to 1-1/2" grid so you have more rivet sectional area and distribution of the load on the vertical 0.080" seat transverse.

Screws to hold the sold panels down are fine, SS with bedding compound like white locktite or Tef Gel, socket recess button heads will give adequate grip and the rounded head will allow boots to move around smoothly.

through bolting is not as good a concept for this type of boat's structure, lots of rivets in an even grid pattern are much more in keeping with the rest of the boat and avoid point load failure of the softer 5052.

cheers,
kmorin

 

Thanks kmorin .... I leave next month to go work on the boat .. just trying to get all my ducks in a row.