Anyone had any experiences making a 3.75quot; hole through a Lewmar hatch? Use a hole saw, saber saw, what? Any horror stories that will convince me to leave it to the experts? Bill
I just installed 2 Nicro Day/Night 2000 solar vents in my Beneteau First 285. A Stainless vent in the Cabin Lewmar hatch. and the plastic version in the aft porthole off the stern. The aft installation was the more difficult because of the angle you had to cut on. I had more trouble finding the 3-3/4quot; hole saw. The normal mass market hardware didn't carry. How to use my good old local hardware. Hole saw has to be much easy than a saber saw.
Bill: It can be done with the saber saw, but it makes a much cleaner job and is much easier with a hole saw. You can actually rent them from Nicro. If you use a saber saw, be sure that you do not let it dance on the plexiglass. It can crack the the glass. You should also put tape over the plexiglass so the saw does not scratch it too. It is easier to see where to cut too.
I have used a Roto-Zip with the circle cutting attachment for several projects cutting into the fiberglass deck and plexiglass hatch. It cuts clean and give you confidence in the accuracy of the tool.
I have a DeWalt version of a rotozip that I used for the installation on my hatch and it worked beautifully. The only problem was that the box said it was a 3-inch vent, so I cut a 3-inch hole. Turns out the vent was 3.25-inches, so my hole ended up ugly. But either way, the circle attachment worked great to start, then I expanded it by hand without too much trouble. Some pictures of the project are at: from : localhost/thaddeus.net/hunter/WindowVent/WindowVent.html
When I installed my solar vent in the forward hatch I drilled the hole as a machinist would - exactly to fit. Well, at least I thought I did. The Nicro vents have a slight taper on the part that penetrates the Plexiglas and while tightening up the screws, the ones on the inside of the hatch, I started hearing an occasional light cracking sound but couldn't see any problems. A few days later I started noticing cracks radiating out from the hole. Upon examination I found the source of the cracks. The taper section was putting pressure on the Plexiglas and causing it to crack. Solution: make the hole slightly larger to allow for the tapered section.
When mating rigid dissimilar materials, it’s often wise to allow an additional clearance, so that the two are not in contact. This allows freedom for differing rates of thermal expansion amp; contraction, and/or flexural movement, where the flexible sealant takes up the strain. Obviously, this clearance will be small enough to be covered by the Vent’s shoulder flange. OMO Gord
When mating rigid dissimilar materials, it’s often wise to allow an additional clearance, so that the two are not in contact. This allows freedom for differing rates of thermal expansion amp; contraction, and/or flexural movement, where the flexible sealant takes up the strain. Obviously, this clearance will be small enough to be covered by the Vent’s shoulder flange. OMO Gord
Thanks for your responses. I have opted for the hole saw and am purchasing one from Practical Sailing Solutions.
I took Rick's advise and used a roto zip to install a vent in my beneteau 350. The Roto was on sale at Home Depot for $75 w/ circle cut and grinder/sander/cutter attachments. Can't wait to find other things to cut,grind..... A co-worker advised that Home depot is good about exchanging these if you kill the motor. Have fun, let's ZIP!!! MArc
The new quot;superquot; HD the just opened near me rents tools. It will be interesting to see if they rent Rotozips. |
Post at 2011-5-26 00:14
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