Bolting items to frame

[Hophazard]

I'm sure this is a stupid question (wouldn't be my first!), but I've seen many brutus builds with various items (pumps, burners) mounted to the frame. After you drill the hole, how are the bolt threads gripping the frame? Are there any additional tools/parts I need to pick up? Thanks in advance.

 

[Catt22]

You have a few options. Probably the easiest would be to drill all the way through the frame and use ordinary nuts, bolts and lock washers to make the attachment. With square tubing, you will need to go through both sides and use long enough bolts to reach all the way through. You could use locknuts on the bolts and eliminate the lock washers, but that's a minor thing really and either way would work. The next option would be to drill and tap the holes then install the bolts. This would eliminate having to drill through both sides and you would not need the nut. The third method would be to use self taping sheet metal screws. With these, you drill a hole of the proper size and the screws will cut their own threads as you screw them in. The third method may be tricky as sometimes the pump motors (depending on which you have and how the base plate is attached to the motor) will get in the way when trying to use a ratchet or any bulky tool. It can still be done using an open end wrench or similar tool, but it's just a little more tedious if that's the case. When drilling the holes, you will want to be as accurate as you can when locating them. Same when drilling all the way through the frame. You want the holes to line up closely. If you screw up and have problems with the hole alignment, you can often enlarge the holes on the pump base plate which will permit more play. Should you need to make the holes really large, you can always use large flat washers to compensate, but this is generally considered bad form among good fabricators.

 

[Hophazard]

Thanks for the quick reply Catt. I'd like to avoid drilling through both sides of the tubing for the moment (just because I don't think it would look as nice), but would tapping the holes or using a self-tapping screw be able to hold given how thin the tubing is? I was looking at using .065" wall steel and wouldn't think that would allow for many threads for the bolt to grip.

 

[Catt22]

That's just over a 1/16" thick wall and it would be much too thin to tap. The self tapping screws would work though. They have coarse threads and are designed for use on sheet metal. I would use the largest size hex head self tapping sheet metal screws that you can fit through the mounting plate holes for the most secure and durable mount. Be sure to use the correct size drill bit for the screw. That's very important. I agree that it would look best if you don't drill all the way through both sides. You can always go that way later on if need be.

 

[PDawg]

Using .065 wall tubing I would go all the way through and use two large wide washers so you don't "crimp" your tubing. Just my .02 cents worth.

 

[Photomask]

Drill through one side and use riv-nuts.

 

[lincoln]

+1 for riv-nuts /nut-certs
+1 for self tapping screws

I am a chippy and I approve this message.

 

[Catt22]

I like those riv-nuts. Those are new to me. I had to google them up to see what they were. Very cool, but the special tool makes that a pricey option. I would buy one as I am a tool freak, but might be over budget for most others.

 

[lschiavo]

I use these all the time:

self tapping and available in many sizes. You just need a drill and hex driver.

 

[Ricand]

I'm not sure if you have a welder, but I've been successful at tack welding nuts to the frame. You can use them as stand offs, not a bad thing to keep rust from behind the pump mounts.

You could always do this and make your own riv-nut tool.

 

[Hophazard]

Thanks for the replies. The rivnuts seem pretty cool and I may end up using them to bolt the wind-shield bracket to the frame (I plan on mounting the burners to the wind-shield like diatonic did). I found this tool that might be worth $25 given that I'll use it for all for 16 rivnuts.

However, I also read a few articles that mentioned you're pretty screwed if you strip the rivnut thread - the bolt will spin and you won't be able to remove the rivnut. After further exploring build threads, I think I may just weld angle iron to the frame, drill holes and mount the pumps with a plain old bolt and nut. That seems to be the most popular route and would explain why I didn't find much info on mounting pumps directly to the frame.

 

[lschiavo]

However, I also read a few articles that mentioned you're pretty screwed if you strip the rivnut thread - the bolt will spin and you won't be able to remove the rivnut.

I can see that happening. If the bolt gets siezed to the nut, there is nothing much to keep the nut from spinning. Hacksaw time then

 

[lehr]

Riv-nuts and counter sunk screw's is how I roll...or I mean fasten !

 

[Photomask]

I can see that happening. If the bolt gets siezed to the nut, there is nothing much to keep the nut from spinning. Hacksaw time then

If installed correctly, riv-nuts hold up surprisingly well. I've been using them for 20 years with excellent success. Now if you feel it is necessary to over-torque every fastener you install, then you are already used to broken bolts, stripped nuts and rounded heads. You know who you are and riv-nuts are probably not for you.

Hacksaw? What's a hacksaw? I have a Sawzal, a Tigersaw, a vertical bandsaw, a horizontal bandsaw, a chopsaw, a hot-saw, a cold-saw, a saber-saw, a jig-saw, a portable bandsaw, a coping saw, a jeweler's saw, a zip-saw, a scroll saw, a trim-saw, a few circular saws, a gents-saw, a recip-saw, a tenon saw, a back-saw, a miter-saw, a compound miter-saw, chainsaws, several japanese wood cutting saws and many more. What's a hacksaw?

 

[Hophazard]

If installed correctly, riv-nuts hold up surprisingly well.

Hm... I may give them a shot afterall. My goal is to make the rig as clean as possible and they seem to be the simplest method. Will probably still weld some flat steel to the middle beam to allow the pumps to be mounted a little further back so that the heads don't stick out as much. Does any one have any experience with this tool (if it's needed to install rivnuts at all)?

 

[lehr]

Mine looks just like a pop rivet gun.

Pat

 

[Photomask]

Mine looks just like a pop rivet gun.

Pat

Mine looks like a big pop-rivet gun too. I have a few others that I use on bigger sizes that operate similar to the home-made one shown earlier. I have used a pneumatic one that works similar to a Jo-Bolt gun but I don't own one.

Once installed, it's a good idea to put a drop of oil or dab of grease on the threads prior to the bolt. It will keep the two from rusting together if you're using them in an environment that has the possibility of getting wet.

 

[lschiavo]

If installed correctly, riv-nuts hold up surprisingly well. I've been using them for 20 years with excellent success. Now if you feel it is necessary to over-torque every fastener you install, then you are already used to broken bolts, stripped nuts and rounded heads. You know who you are and riv-nuts are probably not for you.

Hacksaw? What's a hacksaw? I have a Sawzal, a Tigersaw, a vertical bandsaw, a horizontal bandsaw, a chopsaw, a hot-saw, a cold-saw, a saber-saw, a jig-saw, a portable bandsaw, a coping saw, a jeweler's saw, a zip-saw, a scroll saw, a trim-saw, a few circular saws, a gents-saw, a recip-saw, a tenon saw, a back-saw, a miter-saw, a compound miter-saw, chainsaws, several japanese wood cutting saws and many more. What's a hacksaw?

I have never used these riv-nuts so everything I say is just speculation.

Ha, Ha. I have a guod number of the saws you mentioned also. Sometimes a good old hacksaw is just the right tool though.

Here is what hacksaws look like:

Check your saw storage building...maybe you do have one.

 

[Photomask]

Ha, Ha. I have a guod number of the saws you mentioned also. Sometimes a good old hacksaw is just the right tool though.

Here is what hacksaws look like:

Check your saw storage building...maybe you do have one.

If I do, it hasn't seen the light of day in more than a decade.

 

[cdavidson]

You could use nut plates. Drill 3 holes. 1 for the bolt you want to mount and 2 for blind rivets to hold the nut plate. I have gotten used to using these because of the work I do for the Air Force.

 

[BrewBeemer]

I would use Hexnuts as they are stronger than Rivnuts being hexagon in design vs round preventing them being spun loose.
Plan "B" would be to drill thru the box tubing and rosette weld studs on the back side. Hi Pat!

 

[Photomask]

Welding hex nuts ruins the tempering and they no longer have any strength, provided they had any to begin with depending on grade. Don't forget to re-tap them as welding usually messes up the threads. Throw in zinc or cadmium plating and/or galvanizing and you run a risk of metal fume fever. Yes, they are small and there would be little exposure but don't risk it. If you do pursue that path at least get un-coated parts to weld or get the plating off of them first. If you're unaware of metal fume fever, Google it up. Dangerous stuff, I've had it before and thought it was the flu. I got it from working near somebody else that was welding plated steel. I work with a guy that got it while working one floor underneath two guys that were doing that kind of welding.

Beyond that. There's always another way to skin a cat. Heck, open up the backside of the tubing, put in a 1/2in thick piece of A36, weld in shut, then drill and tap. If you're mounting a pump, a bracket, a panel or something else along that line... riv-nuts are effective, fast and easy.

 

[Hophazard]

If you're mounting a pump, a bracket, a panel or something else along that line... riv-nuts are effective, fast and easy.

Going to head to the hardware store this weekend to see what they have in terms of rivnuts and gun to use for mounting the wind shields. As far as the pumps, after some more searching, I think I'm just going to cut an additional 5" of 2x2, weld it to the back of the middle beam and mount the pumps there using a bolt and nut for the open tube and self-tapping screws into the middle beam. Will let you know how it works.

 

[Catt22]

There is another option. You could use a couple of large worm gear type hose clamps and simply band it to the frame. Might not be as aesthetically pleasing though, but it would be simple and reversible. It would also allow you to remove the pump easily for maintenance etc.

 

[BrewBeemer]

Welding hex nuts ruins the tempering and they no longer have any strength, provided they had any to begin with depending on grade.

Your wrong as Hexnuts are not welded in place, installed the same way as Rivnuts but have a hexagon body vs round preventing them from spinning.

 

[lschiavo]

installed the same way as Rivnuts but have a hexagon body vs round preventing them from spinning.

Are you talking about these?

how do you make the hex hole? I would assume a punch of some sort? I would have a lot more confidence in these not spinning out.

 

[BrewBeemer]

Are you talking about these?

how do you make the hex hole? I would assume a punch of some sort? I would have a lot more confidence in these not spinning out.

Forced fit in setting it as it broaches its way thru the round hole.

 

[Hophazard]

Forced fit in setting it as it broaches its way thru the round hole.

So is it fair to say that I could drill a hole barely bigger than the hexnut, insert the body into the hole, insert the hexnut into the body and then tighten , which would expand the body against the wall and hold it in place? I haven't been to the hardware store yet so all of my knowledge of these comes from this thread and the interwebs.

 

[Photomask]

Your wrong as Hexnuts are not welded in place, installed the same way as Rivnuts but have a hexagon body vs round preventing them from spinning.

I thought you were talking about standard hexagonal nuts and welding them to the frame. Rivnuts have a serration the grabs the hole as they are installed and crimped in place. I go through a few thousand a year and never have problems with them. People that do have problems with them have usually drilled the hole too big.

 

[BrewBeemer]

I thought you were talking about standard hexagonal nuts and welding them to the frame.

NO! I said broached as this is what the hexagon nut does when seated into the hole.
A Hexnut seated will broach making a hexagon hole that not spin out vs a Rivnut even when the Rivnut's installed with the correct pilot hole. Dealing with both types myself many times I have nothing to do with Rivnuts had my shop order Hexnuts only. If Riv-nuts work for you go at it, I prefer Hexnuts with anti-seize on the bolt threads for easy future bolt removal.

 

[BrewBeemer]

I thought you were talking about standard hexagonal nuts and welding them to the frame.

NO! I said broached as this is what the hexagon nut does when seated into a round hole making the hole hexagoned.
A Hexnut will not spin out vs a Rivnut even when the Rivnut's installed with the correct pilot hole diameter. I can't explain it simpler. Dealing with both types myself many times I have nothing to do with Rivnuts, always had my shop order Hexnuts only. If Riv-nuts work for you go for it, I prefer Hexnuts with anti-seize on the bolt threads for easy future bolt removals.