Cutting a hole in the deck

[dawnhoff]

I need to cut a 3 1/4" hole in the deck of my Venture 21 for for a solar vent. Any sugestions on the best way to cut the hole?

[sailingdog]

You could use something like this. Or you could scribe it and use a jig saw.

[sailingfool]

Originally Posted by dawnhoff

I need to cut a 3 1/4" hole in the deck of my Venture 21 for for a solar vent. Any sugestions on the best way to cut the hole?

Assuming you will cut through core material, be sure to seal the edges of the hole to protect the core material, or you'll have a soft deck in no time.

"Seal" - chip out a 1/2 inch of core all around the hole, then fill the area opened with a mix of West epoxy/collidial silica.

[sailingdog]

Also, pot the holes for the bolts. The holes should be drilled oversized and filled with thickened epoxy as well, and then counter-sink the top edges of all the holes, those for the fasteners and for the vent fan itself, so that the sealant has a place to form an o-ring when you tighten the bolts down.

[Quickstep192]

I would use a hole saw like the one shown here . Run it backward at first to get started; that will prevent it from digging in. New hole saws are very sharp and the sharp teeth can dig in, grabbing the material and either chip it badly, twist the heck out of your wrist or both. If you can reach the underside, go halfway through from the top and finish it off from the underside. That will help prevent it from chipping out. If your deck is cored, follow the sage advice above. In fact, if it were me and the deck was cored, I'd think real hard about how much I wanted that vent.

[sailingdog]

i don't think they make a standard hole saw in that diameter.

Originally Posted by Quickstep192

I would use a hole saw like the one shown here . Run it backward at first to get started; that will prevent it from digging in. New hole saws are very sharp and the sharp teeth can dig in, grabbing the material and either chip it badly, twist the heck out of your wrist or both. If you can reach the underside, go halfway through from the top and finish it off from the underside. That will help prevent it from chipping out. If your deck is cored, follow the sage advice above. In fact, if it were me and the deck was cored, I'd think real hard about how much I wanted that vent.

[sailaway21]

Drill a small hole through the deck and then use a jig saw with the finest tooth blade you can find. It's not a bad idea to find the center of your hole and then cover the deck with masking tape. Then scribe your hole's outline on the tape and cut away. The tape will minimize chipping around the edges. Also make sure that your jig saw blade is squarely aligned in it. Test it on a piece of wood of approximately the same thickness of your deck. Most jig saws are adjustable and most are not square even when the guage says zero degrees. You don't want to cut a tapered hole!

A hole saw, if you can find one (try a commercial supply house), will do the job fine but I strongly recommend the two cut process mentioned above. The hole saw will be kind of expensive for just a one time use. And the above poster was not lying about the amount of torque it'll put on your wrist!

[badsanta]

I cut the hole in my plexeglass hatch, I did not want to do the deck. At the worst I figured I could replace the hatch easer if I messed up. Works great.

[RXBOT]

Agree with santa but don't think 21 foot venture has a hatch besides companionway. But if main reason 4 vent is 4 when u r away from boat could u put in companionway hatch?

[Rockter]

I wonder is it worth it, for a solar vent?