Help with angles...

[johnoutdoors]

I am just beginning to weld. I have decided that the best way to have ideas for things to weld is to give the projects to people as gifts. One of my neighbors owns a canoe/raft livery on the Delaware River. I decided that a good project/practice piece would be to use pipe to weld up a raft for her. I got the general shape right, I can do the math telling me what degree to cut the angles to.

The issue I am having is how do I tell the pitch of the cut, that is to say, is there an easier way to decide how to cut the angles to give me a flush welding surface to make a 3D object like a raft. I want the long sections to be flush to the mounting surface, at each end it should turn up appox 15 degrees, then meet a perpendicular (to the long sections) that will be the front/rear of the raft. I cut all of the angles to 22.5 and that works, but how do I manage the rotation.

I have an angle grinder, circular saw with metal blades, tons of clamps, but I am short on knowledge on how to manage the pitch of the angles. Any tips or resources that you can point me towards? Thanks in advance.

 

[EdT]

Not sure I understand the question or the project, but it sounds like you're trying to figure out the cuts for a compound angle. That is a joint that has angles in two planes as opposed to a simple joint which is in one plane. Google "cuts for compound angles in tubing" and you may find what you want. If your friend's canoe thing is a business or even a private dock, you may want to consider that something that can hurt someone if it fails may not be the best place to learn how to weld.

 

[FunkyfullWidth]

Get good at math.. Go out and get a tubing angle finder.
The best way to figure a structural project like that is to write it all out on paper, figure your angles there. then use a angle finder to spin it however you need.

A flotation device is a hell of a "learning to weld" type of project.. What's next, landing gear for an airplane? what kind of welder did you get? don't forget to bevel the edges of the pipe for max penetration. Assuming it's thick enough to warrant that.

 

[mrolds88]

I think this might be what you are looking for. http://www.trick-tools.com/ALB002-Wixey-Digital-Angle-Gauge-Bracket-8108
Digital version of the old protractor that used to be used for exhaust pipe work.

 

[Kevin54]

I am just beginning to weld. I have decided that the best way to have ideas for things to weld is to give the projects to people as gifts. One of my neighbors owns a canoe/raft livery on the Delaware River. I decided that a good project/practice piece would be to use pipe to weld up a raft for her. I got the general shape right, I can do the math telling me what degree to cut the angles to.

The issue I am having is how do I tell the pitch of the cut, that is to say, is there an easier way to decide how to cut the angles to give me a flush welding surface to make a 3D object like a raft. I want the long sections to be flush to the mounting surface, at each end it should turn up appox 15 degrees, then meet a perpendicular (to the long sections) that will be the front/rear of the raft. I cut all of the angles to 22.5 and that works, but how do I manage the rotation.

I have an angle grinder, circular saw with metal blades, tons of clamps, but I am short on knowledge on how to manage the pitch of the angles. Any tips or resources that you can point me towards? Thanks in advance.

I can help you out with your angles but I first need to see what is going on in your head. On a cut, you won't have a "pitch". That is for screws and roofs. Also if you want "sections to be flush to the mounting surface, then turn up at a 15 degree angle, what angle is your mounting surface? Too many questions in what you are doing and not enough information.

Can you put up a sketch of what you are wanting to do? That may make it easier for us to understand. I have a drawing package I can use to make a quick blueprint and it will give me the angles you need, but I need something to go on first.

 

[gungatim]

when I worked for a welding supply co. we made a product that you trimmed to the angle you wanted, then wrapped around a pipe for a one-time use cutting guide. forget what it was called, curv-o-mark or something...maybe not really answering your question, but if you lay it out to whatever line matched closest, you had your angle...I'm sure someone still makes these...if that helps at all...

 

[KaiserJeep]

a good project/practice piece would be to use pipe to weld up a raft for her.

I'm envisioning a small raft, like something to sit on a mantle. Correct?

 

[johnoutdoors]

A flotation device is a hell of a "learning to weld" type of project.. What's next, landing gear for an airplane? what kind of welder did you get? don't forget to bevel the edges of the pipe for max penetration. Assuming it's thick enough to warrant that.

Google "cuts for compound angles in tubing" and you may find what you want.

I'm envisioning a small raft, like something to sit on a mantle. Correct?

Sorry all, I probably was so wrapped up in what was in my head that I didn't explain well. Yes, this is a foot long raft made of 3/4 ID black gas pipe. I am in no way trying to make load bearing/structural/floatation/life dependent thing any time soon. It will be for her desk or mantle.

Compound miters are exactly what I was trying to ask about. Shame on me for not thinking about it in those terms. For all of the crown molding I have done, there was a block in my mind and the two skills didn't mesh in a way that I could make sense of it. Sometimes things are simpler than they seem.

The problem I was having was that I didn't factor in for the rotation of the cuts from one end of each section to another. I was having some joints flush and easy for me to weld, and others with a 3/8-1/2" gap on one side while touching on the other. Thanks all for the replies.

 

[joe49]

15 up in one joint? 8 joint 180's?

 

[johnoutdoors]

15 up in one joint? 8 joint 180's?

Picture a whitewater raft. Its essentially an octagon with 2 long sides. That's the 22.5, mitering the 4 joints. The short front and rear of the raft are higher than the sides to provide rocker for obstacles. 15 degrees was a guess as I needed a number and that seemed like enough to be noticeable without being too high to appear odd.

 

[joe49]

15 up in one joint? Easy way 1st joint cuts 7.5, second joint cuts 22.5 two right pieces, two left pieces at 90 deg to 7.5 cut. Then continue 22.5 cuts in turn sections. Also in small sizes I usually use 22 to 22.25 instead of 22.5.

Compound easy way lay up pipes with square cuts at angles needed, then find angle of compound cuts with protractor.