Changing motors. Old bolt holes??

[The Mad Cat]

I'm puting different motors on the boat and have to drill new holes so what should I do to the old holes " sika flex"?
Also because there will be extra holes should I strengthen the transom with a backing plate.
Any suggestions appreciated.

TMC

[Steeler]

Dowel,gelcoat and maybe a nice piece of timber between the motor and transom.

Steeler

[dreemon]

You might find that the holes still match up with the new motors, I had an old johno that came with my boat and changed to a yam, went in the same holes :D,

if not, I might just fill with resin. but always use an engine pad and sika all around everything. Cheers

[The Mad Cat]

Hi Dreemon,
Please excuse my ingnorance whats a "engine pad"?
Unfortunatly the holes don't line up.

TMC

[FNQCairns]

depends, how old is the boat? Is the transom still good for 10-20 years??

If it's all still good and you would like to keep it that way ream the hole out a little, just enough to find new uncontaminated material then use thin epoxy to coat and soak the hole then shortly after epoxy/talcum powder mix to fill the hole proper, this will seal forever or you can use polyester resin in just the same way.

If you don't need to care too much use a marine polyurethane sika or 3m product. These will seal for a very long time, it's just a little rough.

[dreemon]

TMC, the engine pad or " transom outboard pad" is like kitchen cutting board plastic and is placed between the transom and outboard mounting bracket, it helps spread the load like a washer also protects the hull finish. good idea to use oversized washers in the engine well or a plate for the same reason.

bummer the holes dont line up . Cheers

[The Mad Cat]

Thanks Dreemon,
I thought it may have been a manufactured pad, so no trouble for me to slip into the kitchen when nobody is looking then act dum in the aftermath.

TMC

[oldboot]

Um... domestic kitchen cutting board will be a little too soft and inconsistent...and will have a surface texture.

you can buy ready made mounting pads..or go to a plasics company that custs to size and get a piece of HDPE.....not that expensive... but a "specified" plastic, harder and with no voids or bubbles.

If it is a glass or timber boat, you want to seal up any hole you make, so water does not get into the frame......thin marine epoxy ( west system, boat coat, system 3 or similar) is by far the best for this.

This applies to both the old holes if some one didn't do it lats time and the new holes you will drill.

If the old holes are properly sealed and above the water line, there is no real need to fill them...unless it makes you feel better.....besides the new mounting pad will cover them.

cheeers