So you just finished building your Certiflat weld table. Congratulations! Now what? Now you need a way to clamp your materials to the table before welding them together to make your final part. How do you obtain said clamps? Well there are two ways. The first way would be to simply buy them, but these can run between 20 to 25 dollars each. Your second choice is to make your own and save $15-$20 per clamp. The bill of materials is rather short and simple. Your choice of clamp, and a 5/8" bolt (optionally you could use 5/8" OD solid round stock). In this example, I'll be using 6" bar clamps from Harbor Freight. At the time of this build, they were 2.99 each.
6" bar clamp from Harbor Freight:
Step 1: Prep the Bolt
Now that you have gathered your materials, it is time to prep your parts. Remove all coatings from your bolts-you don't want anything to contaminate your weld puddle, and you especially don't want to breathe in anything that might be harmful to your health. Cut the threaded section from the bolt. Another option would be to use a 5/8" solid round stock in place of the bolt. You could also leave the threaded section in place and use a nut to bolt the clamp to the table through the table top.
A little warning about coating and the dangers of welding:
Step 2: Prep Your Clamp
We are only interested in the tensioning portion of the clamp. The fixed jaw portion needs to be removed. You can simply use a saw (band saw, hack saw, or sawzall) to cut the fixed jaw off, or you can drive out the pin if your clamp is so equipped. If you are choosing to remove the pin, grind down the side that has been mushroomed over down to the base metal of the clamp. Once it is ground down, you can drive it out with a drift and a hammer. Remove the fix jaw portion of the clamp. Remove any paint or powder coating from where the fixed jaw used to reside.
Step 3: Welding Time
Tack your clamp to the head of the bolt or top of the round stock (if you chose to go with that option) using your preferred welding process. I chose to TIG mine together. You want to ensure that the clamp sits at an angle relative to the head of the bolt so as to create a binding action between the bolt and table top when tension is applied via the clamp. Once you are satisfied, everything can be fully welded.
Step 4: Final
Once everything has cooled off, insert it into your table and clamp something down. If all has gone well, you should not be able to move the piece you just clamped down! You can use this method for just about any sort of clamp as long as it is steel and can be welded.
You can follow along with our Youtube video that outlines these steps: