| Author | Message | ||
| Nick Morris (Nick3751)
Rating: N/A |
I've got to cut a hole in the roof for the tank vent. Since the roof on mine silver sides is almost completely curved I'm going to have to put a verticle pipe through a hole in a sloping roof. I'd like it to fit a snug as possible when I put some sort of gromet in it (suggestions in this area are welcomed as well). I'm guessing I'll be the best off to cut a piece of cardboard to the curve of the roof then cut a piece of pipe to that curve and use that pipe to draw my hole on the roof then cut it with either a jig saw or drill lots of holes to make the cut. Is that what ya'll are thinking? | ||
| John MC9 Rating: N/A |
There will be arguments otherwise, but side-wall venting is another option. | ||
| Gary Stadler (Boogiethecat)
Rating: N/A |
I used a hole saw with a very long guide drill bit for the center. If you hold the saw at the same angle the pipe will go thru, it cuts the proper shaped hole... simple... I used a saw that was almost exactly the same diameter as the pipe for a close fit, and then for the gasket I got a little exotic... In the electronics industry there is a silicone made by GE, RTV167. The stuff is light grey, it is not the familiar acetic-acid curing stuff you're used to... instead it cures by evaporating methanol that was mixed in at the factory. Bottom line is, the stuff is amazing. It's $34 for a toothpaste sized tube, so it oughta be amazing. It sticks to almost anything with a vengeance, and it is exceedingly strong... much more so than any silicone I've ever messed with before, and just a small bead inside and another small bead outside has kept my vent completely attached and sealed thru all kinds of nasty weather for the last 4 years so far. I'd recommend it.. it's not paintable but that's not a big deal... You can get it online at Mouser: click here | ||
| JR
Rating: N/A |
Use a holesaw in a large, slow turning drill. Something you can hold on to. If the drill is kept vertical, it will cut the correct sized hole even in a curved roof. Be careful that the hole saw doesn't "walk" out of the hole when first starting the cut. Wouln't get the vent too far out into the roof curve...may look a little odd. Mine sets about 2' inboard and runs up thru a closet. The pipe can be offset without issues. JR | ||
| captain ron (Captain_ron)
Rating: N/A |
Nick, funny you posted this question as I am going to to the same job in the morning. I was going to use the same method you posted. I have long bits that I can go up through inside which I may have to do because I'm putting mine in a devider wall and need to make sure I hit the wall on center. I still may find a different place to run it such as my rear cap which would be easier to put through and can be less of an eye sore on the outside. | ||
| R.C.Bishop
Rating: N/A |
I've heard tell of a guy who, under similar circumstances, went to the bottom side of the room, got the exact place where he wanted the hole then....shot a 22 bullet thru the interior....and walla....knew exactly where to draw the circle in the roof...........  For my purposes, I do it exactlly the same way, though with a drill bit through the bottom; cut the angle of the slope on the top (which should be measured with a small level and a ruler)in the piece of pipe; mark around it on the top of the roof and use a hole saw.....then, if necessary, use a Dremel or other tool to smooth out the oblique if any. The difference should be minimal. There is usually cover that will fit over the pipe which will "take up the slack". Seal with a paintable sealant, clean off the edges with Mineral Spirits, Naptha, or Acetone, and you should have a great, professional looking job. FWIW Wrotsa Wruk!!! RCB '64 Crown Supercoach | ||
| motorcoach1 Rating: N/A |
i used a 22 degree pipefitting at the top and fitted it so as the pipe was square to the roof curve and then the hole was round not oval and the vent cover fit well on the out side | ||
| Gary Stadler (Boogiethecat)
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RC, did I tell you that story? I didn't think I did, or if I did you have a hellofa memory... About 25 years ago I did exactly that (with a 22 rifle) to locate where to cut a hole in my house's sub floor when I was running a new sink vent and didnt want to rip out the drywall in the bathroom to drill the hole.... from the attic I took a single shot down thru the wall at the center of the base 2x4 and then went under the house, found the hole and used it to center my hole saw. Got the idea one night while half drunk with a buddie at a mexican restaraunt... Worked like a dream... ...Oh the good old days of youth.... | ||
| Bryce Gaston (Busted_knuckle)
Rating: N/A |
I ain't got no .22 would a .44 Steel jacket hollow point do as well ? Oh wait a minute I ain't even convert'n a bus! Anybody got 1 I can try it out on! LOL! I tell ya what I love this site as ya never know whats gonna come up next! | ||
| R.C.Bishop
Rating: N/A |
Gary....nope you did not...but I've heard that it used to be quite a common thing to do.....in the woods, no level, no square, etc....must've been our fore fathers... What ingenuity, eh what? RCB PS....don't use a shotgun, I'm led to believe... | ||
| Sojourner (Jjimage)
Rating: N/A |
Hole-saw is the answer to thin metal curve or compound curve surface. Whenever hole-saw cutting thorough sheet of aluminum, I always try to drill a pilot hole first. Then reinstall pilot drill bit into hole-saw back-ward or smooth rod…so that it won’t enlarge pilot’s hole to keep it straight & within size. Another point…drill motor with “bubble” indicator will make your job straighter if coach is level. FWIW Sojourn for Christ, Jerry | ||
| airless in Jacksonville Rating: N/A |
Bryce the .44 prevents you from having to drill.. I strongly recommend. ;) | ||
| motorcoach1 Rating: N/A |
captin Ron if you go through the side there are some nice marine bilge blower covers avalible in SS or plastic. i used a K&S flame arrestor OFF a small carborator on one of mine in the past it look real cool too | ||
| Jerry Liebler (Jerry_liebler)
Rating: N/A |
Use a hole saw, just slightly larger than the pipe's O.D. Drill upward between studs (guides) in a wall with the slowest drill motor you have. Then silicone in the pipe, both inside and outside, and add one of the plastic vent caps, available at any RV parts store, with lots of silicone under the cap's flange. The cap and it's flange will direct water away from the hole should the seal ever fail. This'll work even if insulation is already in but you'll lose the inner silicone seal. Regards Jerry 4107 1120 |