To drill- or not to drill...new thru hull depth

[jshanley]

I have a 1980 O'Day 22 equipped with an aged but functional Raymarine ST30 BiData, speed and depth.

However the depth function is on its way out and I suspect the transducer is failing.

Question is this: the original transducer has a diameter of 42 mm but this item is hard to find and/or expensive. The replacement is 50 mm in diameter, easy to find and about half the price.

So how hard and what are the risks of enlarging the thru hull opening to accommodate the extra 8 mm?

Thanks.

 

[justsomeguy]

I have a 1980 O'Day 22 equipped with an aged but functional Raymarine ST30 BiData, speed and depth.

However the depth function is on its way out and I suspect the transducer is failing.

Question is this: the original transducer has a diameter of 42 mm but this item is hard to find and/or expensive. The replacement is 50 mm in diameter, easy to find and about half the price.

So how hard and what are the risks of enlarging the thru hull opening to accommodate the extra 8 mm?

Thanks.

Easy, and minimal. I think the greatest risk lies in the installation procedure.

 

[kpgraci]

Since you already have a hole in your hull think of it as preventive maintenance. Had there been no prior hole I would go shoot thru.

 

[jshanley]

justsomeguy: Please describe the installation procedure risk. I don't think I follow. Thanks.

 

[justsomeguy]

justsomeguy: Please describe the installation procedure risk. I don't think I follow. Thanks.

Sorry if I wasn't clear.
Not following established, conventional methods is the biggie, but I'm sure you'll be fine, which is why I stated "minimal".

Use a good sealant, properly applied.

A thing is "conventional" because it works. Any deviation is at your own risk.

 

[dparilla]

Get a hole saw kit that can mount two saws at the same time. The inner one will be the original hole size (to keep it centered) the outer should be the new hole size. Then follow any one of the instructions enclosed with the transducer, or from Maine Sail's website for mounting through hulls. Big points are good sealant and solid backing plates.