cutting metal door for a dog door - jigsaw not working!

I have a metal door ( 1/4 inch metal on inside and outside, inner foam core). I am trying to use a jigsaw to cut and the blade keeps popping out of the jigsaw (it is a fine tooth about 16 teeth per inch ). The blade is 4 inches long and I have tried cutting just through one side at a time but did not get very far.

What are my alternatives to getting the opening cut for the dog door?

 

Your blade may be coming off because it may be striking the other side of the door.
You might try a blade that is thick enough to cut both sides at the same time.

 

Thank-you Greg So they make thicker blades. I am trying to see online what I can find, but the thickness does not seem to be mentioned in the specs.

Just a followup note - I counted the teeth per inch and it is more like 13-14 teeth per inch. Not sure if this makes a difference. The blades I got were from a major hardware store. Maybe there is a specialty store that could help? Not sure if there are some store in Pacific Northwest/Seattle area that would have a better selection of blades and more help?

I am trying to cut all the way through both sides of the door and the blade exceeds the width of the door. I have also tried to put a block of wood to just attempt to cut through one side.... this does not work either. Also probably not the best idea to cut through one side at a time anyway?

 

Personally, I wouldn't use a jigsaw. While you can watch your line on the side of the door you can see, it would be very difficult to keep the blade from waving around on the opposite side of the door, as thin blades like to do. It can also leave a rough edge and I bet that the blade is leaving a nice dent in the metal each time it hops.

I'd suggest that you carefully measure each side of the door and mark your lines on each side. Then, either use a 4 1/2" grinder and a metal cutting abrasive blade, or a skilsaw and a metal cutting abrasive blade and cut one side of the door at a time, watching your depth so that you are only cutting 1/2 way through the door each time, and wear eye/ear protection!

I've cut several metal skinned doors open this way and it leaves a perfect opening on each side that does not have a jagged edge.

 

I could rent a grinder and get a 1/8" 4.5" diameter wheel from a local rental store. However....

I am concerned about how steady I can keep the grinder in order to stay one the lines. Do grinders come with some sort of a guide, or how do I keep on the lines? So, having never used a grinder before is this something I can do ( I am wondering?). I am able to keep a pretty steady hand using my other hand to brace against... but not sure how or if it is possible to keep to the lines I mark. Would boards help as guides ( if grinders do not come with a guide?).

Another suggestion from a friend of mine was to get more of an "abrasive" type blade. But note sure where I can find this type of blade, or exactly what it looks like or is packaged like.

 

1/4" metal is thick metal! Are you sure it is that thick? I am like the others, either a grinder or rotozip.

 

I am heading to the store for a grinder. Hopefully they will qwell (sp?) my fears about being able to keep a straight line, or give me some tips. Or I can search online now that I have a more specific question to address? Unless anyone has some tips for me at this point on how to use the grinder.

BTW - You are right, the metal that I am drilling through is more like 1/16-1/8 inch thick. ( I was initially looking a the lip edges of the door and it fooled me into thinking where I was drilling, it would be 1/4 inch thick...)

 

You should have no trouble following a line with the grinder freehand. Just be sure you have on some goggles so that you can watch the line easily without squinting from all the flying debris. I've had to get metal/abrasive ground out of my eyes twice, so I can't stress that enough.

If you can figure out how to clamp a straightedge onto the door to help guide you, more power to ya, but I think you'll find it's pretty easy to control a small 4 1/2" grinder.

You'll want to use the thinnest abrasive blade available. Most hardware stores sell a 1/16" x 4 1/2" metal cutting abrasive blade for about $2 each. The 1/8" thick blades are too thick. 1/16" ones cut through metal skinned doors like butter.

 

Maybe I missed something here, but why not use a metal cutting blade in a circular saw? You can adjust the sole plate to set the blade at the proper depth and you'll find it a lot easier to maintain a straight line cut.

 

why even a metal cutting blade in a circular saw ?

I cut mine with the 40 tooth carbide freud blade I use for everything else , nice smooth cut , blades still working fine for wood

 

Until a carbide tip imbeds itself in your arm. Been there, done that.

 

George,

Yes, you missed something.

>>either use a 4 1/2" grinder and a metal cutting abrasive blade, or a skilsaw and a metal cutting abrasive blade.

 

This may be elementary, and you already thought of it, but take the door down to do this. It will be so much more difficult and dangerous to do it hanging.

 

My dog door is operational! Although the dog is hesitant!

How I got it done: I got the grinder (rental listed it as a 5" grinder) and I bought a 4.5" blade with 1/8 thickness. All went well, although starting made me nervous, but it went faster as I grew more confident that it was going to cut and nothing was going to catch on fire. I did take the door off the hinges, and I wore a breathing mask and safety goggles. There was metal and sparks flying everywhere, and my old ratty garden gloves did smoke a bit and a small hole developed!

But it was easy to guide the blade through the door by hand without any guides (other than the penciled lines!). As suggested a 1/16" blade might likely would have worked better and a made the job go a bit faster. But I saw the suggestion of a smaller blade too late, but all went well anyway.



Thank-you to all for working on this project with me!

 

Congratulations, Lstrom! It feels good to attempt and accomplish something you've never done before, doesn't it?

Be sure to visit us again with your next project, it's a kick!