# How To Cut a Slot in PVC



## dodgeboy77 (Mar 18, 2009)

I am building a fake rocket as a geocaching project (actually, I am only building the engine end - no nose). I am using 3" PVC pipe and fittings and have gotten some 3/16" PVC sheet for use as fins.

I want to slot the rocket body to fit the three fins, then glue them in place. I would imagine I could do this without too much trouble with a jig on my router table and a 3/16" straight bit. Or can I? Will the bit melt the PVC?

Or should I find another way to cut the slots? I've cut PVC on my miter saw without a problem but don't know how it will react to a router. Another option might be to do it with a dado head on the TS.

Thanks,
Bill


----------



## woodnthings (Jan 24, 2009)

*Be careful*

I make a saw kerf on the tablesaw on some 2" PVC down one side. The PVC wants to close back up on the blade so you need a riving knife which I don't have. Nothing bad ahappened, but maybe I was forunate. It also can rotate unless you secure it on a block somehow. I don't know how long you need to make it, but if it's just in from the end a bit you should be able to do it on the tablesaw.... maybe stack 2 blades together? :blink: bill


----------



## dodgeboy77 (Mar 18, 2009)

_<< I don't know how long you need to make it...>>_

I haven't finalized this project, but I would guess the part of the fins where they attach to the body would be around 10" long.

Bill


----------



## cabinetman (Jul 5, 2007)

dodgeboy77 said:


> _<< I don't know how long you need to make it...>>_
> 
> I haven't finalized this project, but I would guess the part of the fins where they attach to the body would be around 10" long.
> 
> Bill



Are you opposed to shaping the fins and just butt gluing them to the side?








 







.


----------



## dodgeboy77 (Mar 18, 2009)

<<_Are you opposed to shaping the fins and just butt gluing them to the side?_>>

The base of the 'rocket' can be unscrewed by way of a threaded 3" PVC fitting to get to the inside 'cache' where the log, etc. is. Because the tail has to be unscrewed, I figured I'd be best off to have the strength of a slotted joint (people will be grabbing the fins to unscrew the base). Plus it will make it easier to align the fins if the body is slotted.

If you are interested in what Geocaching is, there's a short video at www.geocaching.com that gives an explanation (Where it says 'WATCH Geocaching in 2 minutes').

This will be clearly marked so that if someone comes upon it accidentally while out in the woods, they won't think it's unexploded ordinance or anything dangerous.

Bill


----------



## Alchymist (Jan 2, 2011)

As easy as PVC cuts, use a fine tooth handsaw.


----------



## dodgeboy77 (Mar 18, 2009)

<_<As easy as PVC cuts, use a fine tooth handsaw>>
_
It cuts easy enough but a hand saw won't give me the accuracy I'm after. Plus, cutting a blind slot with a hand saw would be tough. For regular cuts, yes, that would be fine.

Bill


----------



## Dominick (May 2, 2011)

I'd take a torch and heat up the PVC till it gets nice and warm. Keep the torch moving so it doesn't burn, then you can cut it out with a utility knife. It'll cut like butter.


----------



## Al B Thayer (Dec 10, 2011)

Woodenthings is right. when you cut PVC pipe it closes in and makes for a messy cut. 

Best off if you fit a plug in it and cut it on the table saw with some kind of stop. There also is a product called Plastaid. not sure of the spelling. This product will weld PVC in any type of joint. Not glue, weld. It's a powder with a liquid hardener. Very short working time but works very very well. I have used it many times. You would not need to slot the pipe and it won't break.

Forget heating the pipe and cutting it with a knife. It will deform and you will have a warped rocket. It won't cut either.

Al

Friends don't let friends use stamped metal tools sold at clothing stores.


----------



## GroovyMambo (Jun 10, 2012)

personally I wouldn't cut it on a tablesaw, if it cracks the flying shrapnel could seriously hurt you. You could try drilling a series of holes and filing the slot smooth with a dremel, or try a multifunction tool.


----------



## jigs-n-fixtures (Apr 28, 2012)

PVC cuts easily with the correct blade Freud makes one that you can buy on Amazon, and most other manufacturers make them to. 

But, I would probably try it with any sharp negative angle blade.

Sent from my iPhone using Wood Forum


----------



## Woodmaster123 (Feb 26, 2011)

Make a jig and use a router. You will be able to rotate it and rout your slots where you want.


----------



## dodgeboy77 (Mar 18, 2009)

Thanks for the replies!

I think I'm going to try Woodmaster's idea. I noticed that MLCS makes an up-spiral bit that they say it good for plastics. I think I'll do a test cut on the router table with a straight 3/16" bit first (because I already have one) to see what happens. If that doesn't work well I may try the MLCS bit. If that doesn't work, maybe the table saw.

Bill


----------



## jschaben (Apr 1, 2010)

dodgeboy77 said:


> Thanks for the replies!
> 
> I think I'm going to try Woodmaster's idea. I noticed that MLCS makes an up-spiral bit that they say it good for plastics. I think I'll do a test cut on the router table with a straight 3/16" bit first (because I already have one) to see what happens. If that doesn't work well I may try the MLCS bit. If that doesn't work, maybe the table saw.
> 
> Bill


Hi Bill - if you want to go with the router table, here is a bit specifically for PVC
http://www.toolstoday.com/p-5175-solid-carbide-double-o-flute-plastic-cutting-router-bits.aspx
:smile:


----------



## burkhome (Sep 5, 2010)

Perhaps a Dremel or die grinder would suffice.


----------



## ponch37300 (Feb 27, 2008)

I'm not very good at explaining things but here is what I would do. I would use a hand router. Make a jig to hold the PVC and guide the router. I would rip some 2x4s at a 45* angle so you have 4 triangles about 3ft long or so depending on the overall length of the PVC pipe. Next make a box of appropriate size, the same length as the triangle pieces and screw the triangles into the corners. Now slit the box in the middle on one side to create a "hinge". The box should be just smaller than the pipe so that you can clamp it down and hold the pipe secure so it can't rotate. Slide the pipe in and then clamp the box shut somehow on the side you cut a slit in, use clamps or screws or a clasp of some kind. I don't think you will need a lot of pressure here. Then build some kind of fence to guide the router so it cuts the slot in the center of the pipe. 

I'm going to try and sketch something so this makes a little bit of sense!


----------



## woodnthings (Jan 24, 2009)

*the real question here is....*

Are these slits AT the end or are they in FROM the end? Because the pipe wants to close in one itself if the end is free, but that's less likely if the slits are made back from the end a few inches.

To accurately make 3 slots at 120 degrees apart or 4 slots at 90 degrees apart will require a jig of some sort or an indexing plug on the end with marks.

A small plunge router with a 3/16" bit which rides on a carriage with no side to side play will do it safely and accurately. The jig and set up will take an hour or two to make and the cut will take a minute or two.... :laughing: 
a guide bushing in a slot will make it accurate or capture the router's base plate between 2 wooden tracks for guides.
:blink: the other bill


----------



## dodgeboy77 (Mar 18, 2009)

Thanks again for all the suggestions. The jig is roughly what I was thinking of making for the router table but the idea of using a trim router/bushing instead is a good one.

At this point, the plan is to combine two 3" PVC couplers by a short piece of pipe - just long enough that the couplers nearly butt together. This will be the 'engine end' of the rocket and will be the part I'm going to cut the slots in to mount the fins. The slots will be about 1/8" deep and can be open ended on each end of the couplers. They won't go all the way through the wall of the couplers so they shouldn't close in.

Bill


----------

