To avoid chipping gel coat.

[Ian_Rob]

I want to cut a hole in the transom of my boat for a shore power socket. I am told that if I initially run the Bosch 70mm Progressor Holesaw that I am proposing to use in reverse that I should avoid cracking the gel coat. Does this work?

 

[solent clown]

I want to cut a hole in the transom of my boat for a shore power socket. I am told that if I initially run the Bosch 70mm Progressor Holesaw that I am proposing to use in reverse that I should avoid cracking the gel coat. Does this work?

yes, but you need to go slow and be patient, and most importantly, keep the saw square to the work piece. For this a good battery drill is much better than a bad 240v drill. It will blunt the saw slightly, but not so much as you will notice unless you are doing it every day. That is all assuming you are cutting the hole from the gel coat side...

 

[lw395]

Depends on several things including gel coat thickness and quality.
Diamond core drill?
Grind the gel off the outline with a Dremel?

 

[Bobc]

Just use a hole saw, but go easy and don't push (just let it work its own way through the gelcoat) and you'll be fine.

 

[salar]

Having drilled loads of holes in my rebuild, I now swear by diamond tile saws like this one http://www.toolandfix.com/spectrum-...nRxO6DGDMkGI9ABixxav_sqFCdj_2iNxoCPRUQAvD_BwE

You will get a really neat edge to the hole. If you are installing a socket there will be a flange covering the raw hole anyway so you would have to make a fearful mess for it to be visible

 

[Ian_Rob]

I now swear by diamond tile saws like this one http://www.toolandfix.com/spectrum-...nRxO6DGDMkGI9ABixxav_sqFCdj_2iNxoCPRUQAvD_BwE

View attachment 68591

Does the absence of a centre bit on one of these cause any problems?

Thankyou.