Drilling Zodiac transom or not???

[Mervyn_23]

I was considering drilling two holes in the transom of my Zodiac Classic Mk II (soft-hull) to secure my 25hp Tohatsu outboard with two bolts & fly-nuts. I do not leave the outboard attached to the boat - I just inflate the buoyancy tubes to their recommended inflation pressure then attach the outboard and secure with bolts before leaving. When the day is over, I remove the outboard from the transom and attach it to the stand in the garage and deflate the tubes a little bit. Can someone, from his own knowledge and experience with inflatable boats / outboards, help me decide whether I should do it or not? I was always told that it is a must since a 25hp outboard is not that portable and very easy to get off the transom and that the boat is rugged and its transom should withstand this.

 

[crazy charlie]

Re: Drilling Zodiac transom or not???

Unless I am missing something here,why would you want to make it more like a permanent mount anyway.Since you take it off every trip out it would be more difficult to get the bolts to line up exactly.i have a 100 lb motor on my Zodiac and I would not want to go any heavier.With a 25hp I would want to make it easier for myself not tougher.Charlie

 

[Mervyn_23]

Re: Drilling Zodiac transom or not???

First of all, thanks for your reply. The reason for drilling the transom and securing the outboard with bolt / flynut is to remove any chance of the outboard getting off the transom and therefore loosing it at sea. Then, before removing the o/b, I unscrew the bolts and then the outboard's clamps and that's it. By getting some help, I don't think that alining the bolts to the holes should be a headache, after all, it was not my intention to go out at sea alone. By the way, which model is your Zodiac and what o/b do you attach? Pls note that my outboard's weight (Tohatsu 25HP 2-stroke) is 51kgs. Any comments? Thanks.

 

[crazy charlie]

Re: Drilling Zodiac transom or not???

Welcome to iboats Merv .My Zodiac is a 10ft SR1 I believe.Powered by a 9.9 Gamefisher(97lbs).I would not call it a struggle but when you are standing in a floating zodiac holding a 100lb motor off the back as you are bending down to set it on the transom.Thats about all the "hold your breath red face"I want.Adding in lining up a few holes and I think that little bit more would put me over the edge especially if a wave was to come by.I try to keep it simple and still enjoy myself.Having someone help you can be as much a liability as it can be a life saver.There was a thread here the other day of someone getting a little help from his buddy as he was installing his motor and his buddy lifted the motor cover lock by by accident and the motor fell in a river as they stood with the motor cover in their hands.Personally I would rather go it alone.Charlie

 

[Mervyn_23]

Re: Drilling Zodiac transom or not???

Thanks for your welcome and for the quick reply. First, I do not plan to attach the outboard when the boat is in the water but when it's still on the trailer. I can't think of a reason why the outboard clamps are loosened when the boat is at sea - I mean, it's very risky, especially when grabbing the outboard from the engine cover. Once I detached the engine cover the first time, I immediately realised that it can't handle the total weight of the outboard. Its locking mechanism isn't strong enough to handle all that weight. When still on the trailer, I am almost certain that it's much easier, considering also that the transom height is parallel to our waist height. I have just uploaded several pics of my Zodiac but they aren't yet online. I will paste the complete URL later on - probably tomorrow.

 

[navigator336]

Re: Drilling Zodiac transom or not???

It's no concern to drill holes through the transom. However, Since you'll be removing the bolts each time out, and therefore can't seal the bolts/holes you should seal the inside of the holes so water doesn't get the the wood. If you drill the holes a little oversize, you could coat the exposed wood surface with some 5200 and still have room to put the bolts through.

 

[Mervyn_23]

Re: Drilling Zodiac transom or not???

Thanks for your reply. I was going to seal the inside with a regular sealer but now that you've mentioned the 5200, I'll search for this product or an equivalent. I was going to further seal the exposed wood by making use of 2 penny-washers (inner diameter the same as the bolt's diameter while the outer diameter is much larger) - one on each side of the transom and when tightening, the washers cut a ring in the wood thus sealing the hole. Any different ideas or suggestions?

 

[BillP]

Re: Drilling Zodiac transom or not???

First off, wood compresses and is easier to keep the clamps tight than on fiberglass...so the problem isn't as bad with your application.<br /><br />There used to be cast alum discs ("motor keepers" or such name)made for this application. They are mounted where the motor clamps contact the transom on the inside and have a lip around the edge to contain the clamp washer and keep the motor from flying off if the clamp got loose. They work very well if you can find them. If you can't find them it is easy to make with a rectangle piece of 1/4" thick aluminum with holes big enough to let the clamp washers pass through. Screw the alum to the inside of the transom and don't worry. If a clamp gets loose you will notice the motor moving around before it goes overboard.

 

[Mervyn_23]

Re: Drilling Zodiac transom or not???

I haven't found 5200 but found Life Calk from Boat Life and Sikaflex 221. Both are sealers / adhesives and can be used on different surfaces including wood. Any previous experience with these products? Btw, here's a pic of my Zodiac Classic MkII.

 

[Terry H]

Re: Drilling Zodiac transom or not???

Mervyn...I like the idea of bolting the motor on the transom...Sikaflex is the metric equivalent of our 3M 5200, but, I would either find a sleeve, gromet, or something mechanical to use with the Sikaflex, or, seal the holes with epoxy. Whatever you use, just inspect periodically and repair as necessary...just a thought

 

[Nos4r2]

Re: Drilling Zodiac transom or not???

Sikaflex is good (it's all I can get over here) but it'll peel off with repeated removal of the bolts. Avon make a screw-on motor keeper.<br /><br />BTw that transom is short-won't the holes you drill end up below the waterline? If you're removing them each time out it'll leak through the holes...?

 

[CaptAlfex]

Re: Drilling Zodiac transom or not???

Why not wire the two transom screw bolts together so they cannot unscrew? That is the recommended practice in most outboard manuals. They also recommend chaining the outboard to the transom with a chain in case the screws come loose. Sure save you alot of trouble of drilling holes and lining up motor. <br /><br />Here is a link to a another quick release system using a "quick release shoe" type device. http://www.zodiacmilpro.com/product/stowables/ <br />Scroll to bottom and click on "View product presentation slideshow here (large file)"

 

[ATVBing]

Re: Drilling Zodiac transom or not???

mine is bolted<br /><br />and sikaflexed