Anything welding

I have a question about weldable primer.

I have a trailer with a frame made of C channel. I'm going to weld a piece of tubing (about 8" long) inside the channel, to support the receiver hitch.

Obviously, I can't paint all the metal after it's welded.

So my question is, is the right to do to paint the metal with weldable primer (after stripping the paint) and then welding it together?

Will the primer protect the metal from rusting?

I think the answer to my question is yes, but thought I would some experienced folks.

Thanks.

 

I would support that plan. Sometimes, you can only do the best you can.

 

That was my hope when I boxed my frame. How well it held up is beyond me since I can't see inside. I hit whatever I can with the 360 degree wand with fluid film when I do it every year though.

 

Harris.

Super missile is nothing new, used for many years in certain repair areas. If you want to cure some insomnia, also search "problem solver welding rod" or pretty much anything from rockmount.

 

Steel-It.

 

I forgot Steel-it was weldable.

I think I will just use that.

Thanks!

 

It’ll be better than nothing but remember that primer is still porous so if you live in an area with high humidity, you’re still likely to have some rust. Steel it is a great option as mentioned above.

 

Thank you sir for the information

 

Yeah definitely not new, just new to me. This was my first time using it. It was recommended for a job I'll be doing so wanted to see what it was like before I actually used it on the job.

I got it here
https://weldingsupply.com/cgi-bin/spider.pl?03SMW30|||700

 

If I am remembering correctly it is an ELC / Higher nickel pseudo stainless rod?

I will have to look it up when I am back home and refresh my memory. I havent run it in nearly 10 years.

 

Picked up this to use with the plasma in conjunction with the sharpe desiccant dryer. Would be handy for me to sandblast the rust off the metal too

 

This is what I was told. When I asked about welding spindles.

"Yea they arent hard to weld. Biggest thing is just to slow the cooling process. Some guys use sand, I wrap mine in a fiberglass weld blanket. Keeps them hot for hours.

I would recommend buying some different filler rod though. I use one called Super Missile Rod. It has a slightly higher nickel content that works great on cast and forged stuff. You can use it on any regular steel also. It flows nicer than ER70, and is more crack resistant"

 

Thats what I was thinking. We used them on some molds and dies, as well as cracked machine parts or heavy equipment housings. We had various sized ovens we used and always went back in the oven atyerwards, back up to a specified temp for an hour or two dwell, then a 24 hour cool down. For small parts we would use preheated sand in a bucket if the ovens were in use.

Pre-heat, interpass, post-heat, slow cool.

I dont miss peening every pass with the scalers, tho.

I should pick some up one day and see if I remember how to use it.

 

To the cutting experts here.

I thought I'd try my hand at something with small details, but keeping it simple.

Downloaded an NC file for some Quickfist mounts. It would've been better to get the actual CAD file but beggars can't be choosers right?

The person that uploaded it got extremely clean cuts as shown -



What I'm trying to figure out, does my cut speed affect making circles this drastically or not?

Consumables have no more than 10 cuts, air pressure set correctly for 12 gauge as well as current (38, minimal dross and barely a bevel).

Couplers are tight, no play or anything as all things before and after cut without issue but here are my results -







I guess the question is, if I had the drawing itself, what settings am I looking to mess with to obtain a clean circle?

I'm unfamiliar with lead outs or pierce delays and the sort.

I have maybe one or two good circles. The others are jagged and one is even an oval so no real consistency in their flaws either aside from jaggedness being the most common issue.

 

Off the top of my head first thing is your pierce height transition to cutting height . Smaller circles are much harder.

This seems to be a problem area for many customers thinking it was a plasma machine problem. We would get a service call. I was the hardware tech .

Then I can be completely wrong

Good Luck

 

On 1/4" I have to slow my speeds way down. Going by memory, I think I'm around 800mm/min.

Even with that, I don't like making holes smaller than 1/2".

I do want to work on my lead ins. Make them curve into the cut instead of right angling them. I have theory that there is play in the table even though I can't see or feel it. I'm hoping leading in after the pierce at an angle or curve will take some of the shock out of the gantry, this have smoother circles.

Again, it's my theory.

 

Could it just be some tables you run up against the table limitations on smaller holes?

 

I don't think it's the plasma table. The table is just the tool holder. It does exactly what you tell it. It can make movements in any direction with an accuracy of 5 decimal points past the whole number.

Laser cutter use the same hardware, but can give a much more accurate cut.

I believe the issue is the plasma cutter settings along with the speed of the gantry. Im more inclined to believe it's the travel speed more than plasma cutter settings.

But like everyone else, I am learning as a go along, too.

 

Most of us guys who are newer to CNC cutting have problems with holes smaller than 3/16" (4-5mm). I know I still do. They do appear at least 1/4" which is where even the more experienced guys start to have problems if they try to go lower.

Your thinking along the right lines. If you can get the file, look into slowing to 60%-70% of cut chart speed (Feed Optimization setting) or so for the circles, check that lead-in is 90 degrees (see linked thread) no radius and length equal to radius (goal, pierce starts in center of hole), and the advice @Bivouac gave is also solid, especially if there was lead-in in play.

This thread has a good discussion on this approach:
Cutting from the Center of a Hole: Fusion 360 - Software / Fusion 360 - CAD - Langmuir Systems Forum

Other things to consider cutting direction vs inside/outside cut, and kerf width if cutting on inside of circle. Inside cuts counterclockwise travel due to swirl of plasma(see below). Diameter of the circle would need to be twice kerf setting plus I shoot for .5-.7mm extra width. Confirm/reduce if needed kerf width setting in your machine profile.



I still have a lot to learn on cutting detail, so if you get conflicting advice from somebody more experienced, definitely take it. I know I've read more experienced guys say for detail on thicker steel, just take the computer out of the equation on stuff like small circles. Meaning, turn off torch height control and initial height sensing (no Smart Voltage) and give the program cutting height. On this really small stuff the computer doesn't have time to calibrate the voltage for THC before the circle is finished. That's part of why you have to slow it down some to give it that time, but kind of a moot point if the circle is almost finished before THC understands what the voltage target should be.

Also remember, Fusion 360 and Sheetcam add .02"(.5mm) of clearance to cut height. So, if you cut without THC and you want example 1.2mm clearance, enter 1.0mm as your cut height.

Good luck. Good starting point is run a few test cuts and check kerf width vs height for 12 gauge.

 

F360 already knows about swirl and the correct direction to travel when cutting circles, so I don't consider those a part of the problem.

Do you have the option to do a "new setup" on that part with the post processor software?

I'm familiar with F360 and with that I have all sorts of control over speeds, lead ins, pierces, tabs.

It's true that THC would not be good for cutting thicker materials.

I've always considered THC was only needed on thinner materials that warp easy.