| Author | Message | ||
| Douglas Tappan (Dougthebonifiedbusnut)
Registered Member Username: Dougthebonifiedbusnut Post Number: 119 Registered: 10-2004 Posted From: 24.63.8.181  Rating: N/A |
Hey Guys, I have to put holes in a polyethylene tank and need to know if I can use a jig saw or will the blade get hot and gum up? It's kind of a shame to buy two hole saws to to make the holes. | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 1224 Registered: 12-2000 Posted From: 74.4.63.215  Rating: N/A |
Doug, If you are going to spin weld the fittings the hole size and shape are pretty critical. I would recommend a hole saw. I have not seen a jig saw used, but I think it could be done if you can control blade speed and use a medium toothed blade (fine tooth will probably be more apted to plug up and coarse tooth may leave a rouhg edge). Also don't get in a hurry, let saw move slowly. Do you have a scap to practice on? Jack | ||
| Cable (Fe2_o3)
Registered Member Username: Fe2_o3 Post Number: 37 Registered: 10-2004 Posted From: 71.112.201.48  Rating: N/A |
Can you rent a hole saw?...Cable | ||
| Douglas Tappan (Dougthebonifiedbusnut)
Registered Member Username: Dougthebonifiedbusnut Post Number: 120 Registered: 10-2004 Posted From: 24.63.8.181 Rating: N/A |
I think you are right Jack, I am using a great type of seal to connect the pipes to the tank so no spin welding. I have no pieces so I will try a more corse blade and go slowly.For the 3" hole maybe I will research renting a hole saw. | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 856 Registered: 8-2006 Posted From: 74.32.83.4 Rating: N/A |
A Roto Zip works great for cutting holes in tanks. I use mine all the time with the circle cutter good luck (Message edited by luvrbus on February 21, 2010) | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 807 Registered: 3-2007 Posted From: 71.53.153.91  Rating: N/A |
Doug, You can use all the methods above, just go slow and that way you won't melt the plastic and reseal the hole after it is cut. A medium cutting blade will be the best to use in my opinion. I use this method all the time. Gomer | ||
| Pete/RTS Daytona (Pete_rtsdaytona)
Registered Member Username: Pete_rtsdaytona Post Number: 602 Registered: 1-2005 Posted From: 97.104.18.110  Rating: N/A |
Lowes will have a "NO or THIN KERF" jig saw blade that makes it easier to cut plastic (Message edited by pete_rts/daytona on February 21, 2010) | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 1065 Registered: 7-2006 Posted From: 74.162.73.114  Rating: N/A |
The RV shops use hole cutters like this'n for what yer doin':  Hole Cutter It cuts cleaner, faster, and it's more adjustable. Just have a steady hand. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1093 Registered: 11-2005 Posted From: 173.202.21.159  Rating: N/A |
If you use a circle cutter be sure to adjust it so the center drill bit goes all the way through to the smooth part of the shaft. If you don't the drill bit will wallow out the center hole and a true circle will be impossible. Also, the surface has to be absolutely flat or the circle bit will grab. | ||
| Matthew Shaw (Greentowtruck)
Registered Member Username: Greentowtruck Post Number: 15 Registered: 11-2006 Posted From: 24.113.12.84 Rating: N/A |
If you use a cutter as pictured above be very careful there is alot of metal rotating that would be easy to get caught in. I own one of those for thin aluminum work but I only use it in my drill press. I personally would use a regular hole saw and they do make them rather coarse with carbide tips that should work rather well. | ||
| thomas flocks (Taflocks)
Registered Member Username: Taflocks Post Number: 151 Registered: 9-2009 Posted From: 74.76.246.165 Rating: N/A |
bust a buck and buy a hole saw $20 is cheaper then messing up your $300 tank | ||
| doug yes (Dougg)
Registered Member Username: Dougg Post Number: 120 Registered: 1-2007 Posted From: 174.131.44.50 Rating: N/A |
What type of sealer are you going to use? | ||
| Don Evans (Doninwa)
Registered Member Username: Doninwa Post Number: 253 Registered: 1-2007 Posted From: 208.81.157.234  Rating: N/A |
Weather you use a fly cutter or a hole saw in soft (plastic) or thin material drill the center hole first and put a piece of drill rod in the cutter/saw to keep from wearing the center hole and making an enlarged hole. In a jam (no drill rod) pop rivet or glue extra layers of the material or something tougher to better resist wearing out the centering hole. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1096 Registered: 11-2005 Posted From: 173.202.17.111 Rating: N/A |
Most hole/circle cutters have a smooth section above the cutting edges of the center drill bit to prevent center hole wallowing. You just have to make sure to adjust the cutter so it uses this smooth section. I fully agree that a hole saw is much better for this job than a circle cutter. (Message edited by gusc on February 22, 2010) | ||
| Don Evans (Doninwa)
Registered Member Username: Doninwa Post Number: 255 Registered: 1-2007 Posted From: 208.81.157.234 Rating: N/A |
"Most hole/circle cutters have a smooth section above the cutting edges of the center drill bit to prevent center hole wallowing." It seems I am always needing to cut holes where I don't want to drill through another layer of material under the hole so the center bit needs to be adjusted so it barely goes through the material thus riding on the flutes. Things like the roof of a vehicle and not drilling through the headliner ect. | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 1230 Registered: 12-2000 Posted From: 74.4.63.215 Rating: N/A |
I have also used a hole saw by first cutting a hole in a scrap of 1/2" plywood, then screw the cutout from the plywood to the surface you want the hole in. The cutout serves as a guide for the hole saw and when done, you throw away the plywood "guide" as well and the plug removed from whatever you wanted a hole in. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1102 Registered: 11-2005 Posted From: 173.202.43.134 Rating: N/A |
Nice technique Jack, I'll put that one on my list. | ||
| L James Jones Jr (Jamo)
Registered Member Username: Jamo Post Number: 127 Registered: 11-2007 Posted From: 24.59.114.207  Rating: N/A |
I use that technique as well, jack. Reboring doors (going to a bigger bore), or boring alum or steel doors, I always use a plywood precut guide. The pilot bit seems to hog out the pilot hole in no time, or the teeth of the (sharp) hole saw like to dig and walk themselves to a new, undesired cutting area. | ||
| Ednj (Ednj)
Registered Member Username: Ednj Post Number: 273 Registered: 3-2003 Posted From: 68.197.93.69  Rating: N/A |
Use Jacks method with a router. The plastic won't have a chance to melt. Clean edges for plastic welding. |