WELDING 18 GAUGE METAL
WELDING 18 GAUGE METAL
(OP)
Can a 16" portion of the part of an existing old door frame be cut and then welded back and ground flush, assuming that the metal is at least 18 gauge (0.042" or 1.0 mm) thick? Please see the attached sketch.






RE: WELDING 18 GAUGE METAL
RE: WELDING 18 GAUGE METAL
Also, consider that cutting out and welding back such a section might cost more than replacing with a pre-hung metal door.
RE: WELDING 18 GAUGE METAL
I did not want to remove the entire door trim because I believe it would be tied back to the block masonry at the sides (but probably not at the top), and on the left side of the door there is only an 8" width of block between the door frame and a concrete column. So if they remove the door frame they probably have to remove the entire block to the left and rebuild it. On the right side is a lot of sensitive communications wiring running along the wall, so the less that the wall gets disturbed, the less likely the wiring will be damaged. If the communications goes down in the building, it will be an unhappy event.
I am uncomfortable packing the channels out to clear the door frame, because I am fastening the channels to the wall with the 3/8" diameter Hilti HY70 adhesive and screens for hollow block, and if that is packed out it will be necessary to design these fasteners for a moment due to the standoff. I doubt that is a good idea or doable but I can check. If I abandon that and use thru bolts, I have no way of determining what shear capacity they have, and no way on ensuring that they fit tght to the block.
How much do you think it is to cut the pieces out if the door frame and weld back, and grind flush? Would it be more than 15 hours at say $100 / hour = $1500?
How much would it be to demolish the whole door frame, buy a new one, install and rebuild the block around it, dispose of the old door frame and old block which will be damaged when the frame is removed? Labour say 8 hours at $60, 2 labourers = $960, plus the cost of a new fire-rated door frame, masonry blocks, and disposal costs = ?
Maybe I should spec it with both options, and let the contractor submit cost for each, but it will leave me uncomfortable that they may damage the communications wiring fastened to the wall?
RE: WELDING 18 GAUGE METAL
Here's another option. Moment splices either side of the door.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: WELDING 18 GAUGE METAL
RE: WELDING 18 GAUGE METAL
1) your moment connection is very innovative! But the offset of the channel at the moment connection may be problematic. Will that cause moment about the weak axis, and horizontal deflection?
2) I am not following how the HSS would be used to shim the thru bolt.
To oldestguy - the floor is all being removed and rebuilt, so I do not think that anything can be supported from the floor.
RE: WELDING 18 GAUGE METAL
The HSS shim idea is show in detail B.
Details C and D show a system hung from the slab above which, I believe, was a previous proposal of your own devising. It would eliminate the door frame issue handily as the channels could stop either side of the door.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: WELDING 18 GAUGE METAL
RE: WELDING 18 GAUGE METAL
RE: WELDING 18 GAUGE METAL