Holding panels together during butt welding can be a challenge. Special so called butt weld clamps are on the market to cure this problem. But they create problems, a HUGE GAP. Often times the gap they create is almost as big as the metal's thickness, not good. A proper butt weld should little no gap, the most gap you should have is the thickness of the filler material, MIG wire is .023.

One can use cleco clamps to hold a sheet metal patch together when butt welding and here is how you do it. The result is a no to very little gap joint, and no special high dollar clamps that create more work.

I use 3/32 clecos, the smallest size they make I have found.
Here is what the cleco and cleco pliers look like for those who dont know.

http://inlinethumb41.webshots.com/26856/2895715800102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2895715800102553149haTcSS)

A great tool to have, its a Roper Whitney hand punch. It can punch various size holes in metal perfect for plug welding. I will use it to make plugs, more on that later.

http://inlinethumb52.webshots.com/17523/2420560120102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2420560120102553149CBGRjn)

If you have an air flanger and hole puncher it too works. I found mine doesnt punch to well in 18ga metal and other reasons I dont prefer using this tool to punch my plugs.

http://inlinethumb33.webshots.com/45984/2829665040102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2829665040102553149OBLuNM)

Holes left after using the Roper Whitney punch.

http://inlinethumb01.webshots.com/44736/2229352750102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2229352750102553149isRYPO)

These are what am after. Once you punch a hole you get a small metal plug, these plugs are used with the cleco to hold the panels together. I will punch several plugs.

http://inlinethumb34.webshots.com/43361/2600924650102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2600924650102553149mMwpKY)

Reason number one why I prefer the Roper Whitney over the air punch. The design of the Roper creates a self centering mark in the plug which allows me to drill a perfectly centered hole in the plug. The picture shows the nice self centering mark.

http://inlinethumb45.webshots.com/44524/2327995880102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2327995880102553149WPKiVT)

Its hard to see but on the backside of the plug a small titty is formed from the self centering mark. Plug with the titty on the left and flat plug on the right.

http://inlinethumb21.webshots.com/44180/2056459910102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2056459910102553149veApSN)

To flatten the plug just use a hammer and dolly, one quick hit will do.

http://inlinethumb02.webshots.com/25793/2486724270102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2486724270102553149COQtUt)

Once the plugs are hammered flat, I lightly clamp them in the vise grip and use a cordless drill to drill the hole. Since the clecos are 3/32 in size you want to use a drill bit around that size, dont go bigger then 3/32, I believe I used three sizes smaller then 3/32.

http://inlinethumb02.webshots.com/25793/2486724270102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2486724270102553149COQtUt)

Not the greatest picture, but the plugs on the left are done with the Roper Whitney hand punch. The ones on the right are from the air tool. The holes on the left are all directly in the center, the ones to the right are off center. I just like the plugs to be holding an equal amount on each side versus being off center.

http://inlinethumb54.webshots.com/20149/2524539040102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2524539040102553149klqpzs)

Better shot of off center holes, try to avoid off center holes.

http://inlinethumb15.webshots.com/43278/2319677040102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2319677040102553149SpMCCH)

Here is the reason behind making these metal plugs. Picture of the plug installed on the cleco. Now we have a cleco with the clamping force to hold a butt joint.

http://inlinethumb40.webshots.com/43943/2045689980102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2045689980102553149wKJZmh)

Cleco is released and the plug is tight against the bottom of the cleco. If the hole you drilled is to big the plug can move around and pull through so proper sizing is important.

http://inlinethumb52.webshots.com/3571/2612633090102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2612633090102553149omFOhG)

My test panel, notice the tight no gap joint perfect for butt welding sheet metal.

http://inlinethumb20.webshots.com/26003/2541504890102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2541504890102553149JxzPUQ)

Another view of the joint. One thing I like to do when aligning panels and I have the fit where I want it is to make some simple alignment marks across the two panels. The marks will help me see if the panel has shifted once I put the panels together for welding.

http://inlinethumb62.webshots.com/20477/2092904180102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2092904180102553149fEsVnu)

Installing the clecos to hold the panels. Not what you want to do but this shows the gap created. There is a trick to overcome this.

http://inlinethumb60.webshots.com/12795/2073214770102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2073214770102553149dRjKpA)

Backside of joint. Now you can see how the plugs come into play. Once again this NOT the desired affect meaning the huge gap.

http://inlinethumb60.webshots.com/45499/2919278900102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2919278900102553149ixBcID)

With the panels clamped back together the trick to achieving a nice no gap joint is..... Drill a 1/8 hole in the center of the joint. You want a slightly bigger hole then the 3/32 stem on the cleco and 1/8 works perfect. Plus 1/8 holes are easy to weld shut after wards.

http://inlinethumb21.webshots.com/45652/2087457430102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2087457430102553149gNDPBS)

When drilling the holes make sure you clamp the panels together. Use long reach vise grips like what is shown to hold them tight.
You can also use a rat tail file if the panels are separated, just make sure you mark the location on both panels for the filing.

http://inlinethumb21.webshots.com/45652/2087457430102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2087457430102553149gNDPBS)

More holes drilled, nothing special, just keep moving the clamp down as you drill.

http://inlinethumb50.webshots.com/25713/2220328330102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2220328330102553149tMGYzV)

Once the holes are done you clamp them together. Clecos are installed and the result is a nice tight joint just like before.

http://inlinethumb35.webshots.com/43362/2293301120102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2293301120102553149EcNSCQ)

Close up of the gap and a 1/8 hole. That gap will be a breeze to weld and so will the 1/8 hole. Much easier the the .040 gap left behind by those high dollar special clamps.

http://inlinethumb03.webshots.com/25154/2477931480102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2477931480102553149OqWOsL)

Another view

http://inlinethumb31.webshots.com/41182/2170691560102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2170691560102553149bmzeMf)

The two panels are sitting level and flush just like they should be.

http://inlinethumb16.webshots.com/45135/2358540190102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2358540190102553149uzyqEg)

Back side of the joint showing the plugs holding the panels tight.

http://inlinethumb55.webshots.com/27958/2545630340102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2545630340102553149mPhwpH)

They hold tight. Panels held with clecos and plugs are solid and with little movement. The only movement you get is from the cleco moving around in the 1/8 hole which sometimes you want to get that perfect alignment.

http://inlinethumb40.webshots.com/43239/2109215210102553149S600x600Q85.jpg (http://rides.webshots.com/photo/2109215210102553149fpGLaR)

Another great write-up and tutorial for us hobbyists!!

Thanks Eric, much appreciated.

good ideas , I am a sheetmetal fabricator & I use the whitney punch all the time, never thought about using the holes that way. The Whitney punch is pricy but I have found them at garage sales & flea markets for just a few $

if you ever need them there are threaded clecos available that pull much tighter than the spring type. #40 through 5/16

Ok Question If your doing this on the car what happens to the plugs when you remove the clecos?

Ok Question If your doing this on the car what happens to the plugs when you remove the clecos?

And to add to this question how do you clamp the two panels on the car to drill the 1/8 inch hole.

Easy,
Put a little tape over the plug and release cleco, or place a magnet next to it.
Shop Vac and blow gun works well if you drop the plug.

Vise grips makes 24" long clamps. I made a few 4ft long clamps out of some from Horror Fright clamps and scrap metal.

You can also mark where you want the clecos, remove the panel and notch it quick with a rat tail file or use an air powered cutoff wheel and make a small notch rather then drill the holes.

good stuff Eric, thanks for taking the time

good stuff Eric, thanks for taking the time

Thanks x2 :yes:

Good post. I'd be willing to bet you can punch the smaller holes and then punch the larger holes using the small holes as the centering guide.


Jerry

Good stuff as always Eric.:thumbsup:

Great write up! Drilling the hole to close the gap, nice tradesman trick. Bob Villa for sheet metal. :thumbsup:

They also sell small aluminum washers for pop rivets that have a 1/8" hole in them. They are cheap and if you drop one it wont rust behind the panel.

They also might have them in Stainless Steel. Never looked for them in SS.

Thanks for the writeup. Good ideas! The pop rivet idea mentioned seems good too since I won't have to purchase a hole punch.

nice and the washer idea saves time

You might find the backup washers as stated for the .093 pop rivets , or use a regular #2 flat washer . The regular #2 flat washer has an ID of .094, OD of .250 and thickness of .032 inch. The ANSI spec that covers it is B27.2 if you need additional info. A good hardware store would have them.

I prefer aluminum for the plugs for two reasons, as mentioned before they wont rust if you lose one, second aluminum is easier on the tools.

You can buy a Roper whitney hand punch copy off ebay for about 20 bucks, the real deal Junior 5 what I show in the pictures is around 80.

Where the hand punches shine is when you are doing plug welds and need to punch holes for the weld. The hand punch has different dies for various sized holes and has about a 3in throat so you can punch a hole 3in from the edge.

The rivet washers is a nice idea, Ill look into those and hopefully they have some that work with my 3/32 clecos...Eric

Great info as always, Eric - Thanks! :thumbsup:

Buying ready made washers will save you some time. I worked in a shop that did composite layups and the molds were made of fiberglass and held together with Clecos during the layup. We used off the shelf washers with the Clecos.