Fishmouths??

[Rancher Ed]

I have been thinking about maybe making a couple gates out of some old pipe we have and have been wondering what the best way to make the fishmouths? (that doesn't sound quite right but I think that is what it is called) on the ends of the pipe so they can be welded to a different piece on pipe.

We have a drill press but its slowest speed is ~750rpm so I am guessing it won't work. We also have drills and 4 1/2" grinders. What would be the best way to go about doing this?

Thanks, Ed

 

[Shield Arc]

If you're going to do it with hand tools, this is a nice template maker. Plug your numbers in, print it out, cut the line, wrap around your pipe, mark, and cut / grind.

Tube Coping Calculator

 

[RPW]

What I've done is just cut a shallow V in the end of the pipe and using 6013 rods to weld. Not necessarily the prettiest joint but it holds.

Good luck.

 

[2manyrocks]

I've made fish mouths with a hole sale in my drill press, and I've cut them out with an angle grinder. I usually keep one grinder with a narrow curf cutting disc in it and another one with a grinding disk. It's fairly quick to cut the V with the cutting disc and then grind out the rest of the profile.

 

[Shield Arc]

I've never done it, but I have read where you can cut fish mouths with your chop saw. A guy posted these angle for the size pipe you're working with on another site.

Pipe / Tube bevels

2.0" to 2.0" tube, base angle of 30*

1.75" to 1.75" tube, base angle of 28*

1.5" to 1.5" tube, base angle of 26*

1.25" to 1.25" tube, base angle of 22.5*

1" to 1" tube, Base angle of 20*

Now to fit different size tubes together

1.75" to 2" tube, base angle of 25*

1.75" to 1.25" tube, base angle of 45*

1.25" to 1.75 tube, base angle of 20*

1" to 2" tube, base angle of 12*

 

[k0ua]

Do these work?

Tubing Notcher - Great Deals on Tubing Notchers at Harbor Freight

James K0UA

 

[Egon]

Torch.

 

[Brad_Blazer]

Do these work?

Tubing Notcher - Great Deals on Tubing Notchers at Harbor Freight

James K0UA

Yes they work okay. You may have to shim out the bracket with a couple of washers to center the cut. I run mine using a big hand drill. I use grease on the shaft/bushings.

 

[crazyal]

Do these work?

Tubing Notcher - Great Deals on Tubing Notchers at Harbor Freight

James K0UA

Yes but there's a few precautions you need to take. The shaft spins on a bushing. You need oil or grease on the bushing or it will get slack that will decrease accuracy. The hole saw makes lots of small metal filings that get attracted to the grease. It's better of you mount it on a drill press (I used a 1/2" hand drill with it clamped into a vise). Also something like WD40 is needed to lubricate the saw while cutting so it will last.

So keep it greased and the grease clean of dirt and metal and it will work great.

 

[Mace Canute]

http://snip.awardspace.com/

or

http://www.ozhpv.org.au/shed/tubemiter.htm

 

[wroughtn_harv]

You have to keep in mind that I've been doing this for almost forty years. I have an edge.

Last weekend I had to finish out an entryway. The material was ten foot sticks of 4 1/2 inch diameter EMT. It's about fourteen gauge. Gap welding isn't any fun with material that thin and galvanized to boot. So a good fit up is critical.

Step 1 is figuring out how deep to cut the notch. the way I figure that is place the pieces together and measure.

 

[wroughtn_harv]

Once I have the depth of cut measurement then I do an arc to each side. That is followed by cutting it out. You can use a torch, plasma, sawsall, grinder, whatever. With this thin stuff I figured the easiest was with a cutter blade on an angle grinder.

 

[wroughtn_harv]

I've used this on pipe from half inch to twenty four inch. I get lucky with it just about a hundred percent of the time.

I have a Vogel notcher, just about all the sure-cuts, and a Williams Low Buck. I use the Vogel when I'm doing a lot of one size. I haven't used the sure-cuts in probably eight plus years. The Low Buck is the trickest, but that's just the way Williams' mind works.

But if you are building a gate or cutting in a once every now and then thing, this works slick and doesn't cost much at all. Plus if you're **** about fit up you can touch it up with a grinder and make it so tight that Ray Charles can sew it up, even if he's blind and dead.

 

[Rancher Ed]

Thanks guy. It sounds like it shouldn't be too hard to mark and then cut them with a cutting disc and then touch them up with the grinder. The pipe is 2" and has pretty thick walls, ~3/16" I think.

Can you use a hole saw at high speed? I was under the impression that steel had to be drilled at slower speeds (>350rpm), is this not the case?

Shield Arc, we don't have a chop saw right now Egon, we don't have a torch either.

wroughtn_harv, those fit very nicely, looks good. (like all your other projects) I am too young to know who Ray Charles is.:laughing::confused2:

Ed

 

[Shield Arc]

I am too young to know who Ray Charles is.

How about Stevie Wonder? :laughing:

 

[Rancher Ed]

How about Stevie Wonder? :laughing:

Nope

 

[Shield Arc]

Dam, what are you............5?

 

[tnjind]

I've never done it, but I have read where you can cut fish mouths with your chop saw. A guy posted these angle for the size pipe you're working with on another site.

Pipe / Tube bevels

2.0" to 2.0" tube, base angle of 30*

1.75" to 1.75" tube, base angle of 28*

1.5" to 1.5" tube, base angle of 26*

1.25" to 1.25" tube, base angle of 22.5*

1" to 1" tube, Base angle of 20*

Now to fit different size tubes together

1.75" to 2" tube, base angle of 25*

1.75" to 1.25" tube, base angle of 45*

1.25" to 1.75 tube, base angle of 20*

1" to 2" tube, base angle of 12*

Hello, I was going to post this from WW myself.

 

[Shield Arc]

Is that where I got it?

Here is how pipe fitters do it.

 

[crazyal]

Do you have a drill press? If so I know plenty of people who just clamp the pipe real good and use a hole saw at low speeds to cut the notch as required.