Fixturing methods

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Being from a more self-educated background I have had a strange journey on the path to learning how to keep metal from moving.After art-school... where they teach none of this, I worked for a designer where we used wood tables, on which we made jigs for whatever we were fabricating. This works fine and for the most part is time effective, but flipping over an object would often mean partial destruction of the jig and would also mean it didn't really work the same on the other side.So fast forward 10 years and I see my first platen table (I know right) That along with a huge number of other fixturing methods were completely unknown to me until about 5 years ago. Now I run my own business, and while I don't have a platen, I do now work off of metal tables. I have a number of angle blocks, and random chunks of steel that I clamp down, a long with large pieces of angle and channel to get to places on the table that are otherwise unreachable by clamps.But I still feel like I spend too much time on clamping. I feel like there is a fine balance out there of clamping the correct distances from the weld are, as well as the correct directions to clamp.So, after searching, I couldn't find any thread on this topic and decided to pick the brains of the pros, semi-pros and seasoned hobbyists out there that have been in the game longer than I have.What are your methods and philosophies when it comes to fixturing and controlling weldment deformation?
Reply:It is hard for me to use too many clamps.Arcon Workhorse 300MSPowcon 400SMTPowcon SM400 x 2Powcon SM3001968 SA200 Redface1978 SA250 DieselMiller Super 32P FeederPre 1927 American 14" High Duty LatheK&T Milwaukee 2H Horizontal MillBryan
Reply:nothing is going to keep metal from moving. I have good fixturing but it still moves. I can just do the work of 2 guys and do it very accurately. I know exactly what 90* (or any degree) is both horizontal or vertical and do not use a tape measure on the fixture table except for a few instances. There is alot you can do when designing pieces to relegate the movement to areas of your piece that are not relevant to the geometry of the final product and how is stands, bolts together ETC. Material thickness, weld sequence, choosing to weld something completely out vs. leaving some seams unwelded all play a part in movement. It is not all on fixturing.
Reply:When I was first getting interested in welding (before I had a welder) I was looking at welding table designs. I had settled on wanting a solid top somewhere between half and 1" thick. After seeing the price for the size I wanted, I decided to settle on 6" slats. Turns out metal is expensive. Ha.   After using it for about a year now, I am glad I did it the way I did it. I measure the slats for flatness every so often. They're all within a very small spec of difference. Less than a 1/32". When I made the table, I made dang sure the top was as square and straight as it could be. I can use the table as a square when I'm welding two pieces on the surface.  I've also made some squares out of square tubing. They work similarly to the magnetic squares, but a little more beefy and you can make them whatever size you need. It helps hold everything square while you weld with allowing less movement that the magnet squares would allow. I'm not sure if this is where you're going with this thread, but that's my $.02.
Reply:@ Flip* - the order you weld up a joint is the way to apply countermeasures to metal shrinkage.  You can not prevent metal from shrinking with a fusion welding process.  Watch Jody's/Roy's approach,http://www.weldingtipsandtricks.com/...tion-tips.html"Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi