Cutting a steel door
#1
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Cutting a steel door
This is probably a dumb question but is it posible to cut a foam filled exterior door? For my basement there is only 73" of space so I would be cutting a lot off a normal 80" door.
#2
You can do it, but how do you plan to attach it to the framework? You won't be able to use the door frame it came in because the hinges won't match up and your door handle will be about knee high. So you will have to custom mortise the opening and door to fit properly. You will have to (or should) cut 1/3rd of the top and 2/3rds off the bottom to still give you some similance of balance.
Cut the door with a circular saw with a metal cutoff blade in it, wear eye and ear protection as it will be loud and you will have metal flying all over.
Post back if I wasn't very clear on this.
Cut the door with a circular saw with a metal cutoff blade in it, wear eye and ear protection as it will be loud and you will have metal flying all over.
Post back if I wasn't very clear on this.
#3
I'm guessing that you are just trying to fit a slab door into an existing opening?
As Chandler mentioned, you don't want the knob to be knee high (sounds funny, but is an easy mistake to make). I'd cut it all off the top to keep the doorknob at standard height. It will also keep the bottom edge (and weatherstripping) as a factory edge. If you cut it with a skilsaw, I'd recommend you only cut through one side at a time, using an abrasive metal blade. Clamp a board to the door as a guide for the saw so that you get it perfectly straight. Flip the door over and repeat. After the top of the door is cut off, you'll want to cut a plug for the top out of solid wood then glue it using polyurethane Gorilla glue, sandwiching it with 2x4's on each side and clamping it until it's dry.
You'll obviously have to remortise new hinges.
If you're actually using a prehung door, you'd have to disassemble the head of the door, cut the amount you need off the side jambs, then reassemble the head onto the jambs. Then you'd measure the size the door needed to be to fit inside your resized prehung jamb, and cut it off the top as described above, then you'll only have to remortise 1 hinge- the top one- unless the top hinge will still work and you don't mind having it so close to the top of your door.
It would also be a good idea to grind or file that new sharp edge on the top of the door. Nothing like slicing your hand on some freshly cut metal.
As Chandler mentioned, you don't want the knob to be knee high (sounds funny, but is an easy mistake to make). I'd cut it all off the top to keep the doorknob at standard height. It will also keep the bottom edge (and weatherstripping) as a factory edge. If you cut it with a skilsaw, I'd recommend you only cut through one side at a time, using an abrasive metal blade. Clamp a board to the door as a guide for the saw so that you get it perfectly straight. Flip the door over and repeat. After the top of the door is cut off, you'll want to cut a plug for the top out of solid wood then glue it using polyurethane Gorilla glue, sandwiching it with 2x4's on each side and clamping it until it's dry.
You'll obviously have to remortise new hinges.
If you're actually using a prehung door, you'd have to disassemble the head of the door, cut the amount you need off the side jambs, then reassemble the head onto the jambs. Then you'd measure the size the door needed to be to fit inside your resized prehung jamb, and cut it off the top as described above, then you'll only have to remortise 1 hinge- the top one- unless the top hinge will still work and you don't mind having it so close to the top of your door.
It would also be a good idea to grind or file that new sharp edge on the top of the door. Nothing like slicing your hand on some freshly cut metal.

#4
I wasn't thinking of a solid slab when I mentioned the proportional division of take off. I was thinking 6 panel. It would be easier if you do use a solid door. That will make your cuts more simple.
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Thanks for the help I still in the thinking stage I don't even have a door bought yet. I just checked at homedepot and lowes for the price to have it specialy done and it was over $150 for the cutting fee. So I am glad to hear that it is possible.
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Respectfully disagree...
Do NOT try to cut the door with an abrasive blade in a circular saw! That method generates TONS of heat which will melt alot of foam core AND burn, bubble and blister any primer on the door. Use a metal cutting blade in a saber (jig) saw. If the blade or stroke is too long (to cut one side at a time) run the tool on top of a 3/4 or 5/4 piece of wood.
Good luck.
Do NOT try to cut the door with an abrasive blade in a circular saw! That method generates TONS of heat which will melt alot of foam core AND burn, bubble and blister any primer on the door. Use a metal cutting blade in a saber (jig) saw. If the blade or stroke is too long (to cut one side at a time) run the tool on top of a 3/4 or 5/4 piece of wood.
Good luck.
#7
I'm just glad the 20 or so I have cut off haven't exploded or caught fire!! You don't cut through the entire door at one pass. You only run the blade 1/4" deep through it. It moves fairly fast, and the heat you create is quickly dissipated. But, cutting with a metal blade and recip or jig is good to go.