Cutting an Opening in residential insulated steel door?

I need to cut an opening in an exterior residential insulated steel door (for a cat door). Any suggestions? Thanks.

 

If it is a smooth finish door, no problem. Drill the holes in the corners big enough for the jigsaw blade to fit and cut away. Stay at least 3 inches away from the bottom though. Use silicone caulk to seal around the opening under the cat door frame. Don't over-tighten the attachment screws.
If it is a door with panels in it you will have to get creative on the placement of the cat door or make some shims to even it out.

 

Been there, done that.

Keep the bottom of the cut about 1 1/2" off the bottom edge of the door. If its a paneled door, it may be tuff depending on the size of the cat door. The smaller ones will work right in the middle between the panels.

Prime the cut edges with a rust preventative primer (I just sprayed some rust-o-leum in a plastic cup and brushed it on), after the paint dries, coat the interior foam core of the door with an exterior caulk of some sort to seal out water as much as possible. Check the fit of the pet door. Try to put some material (sheet aluminum, flashing, vinyl) around the outside of the opening where the pet door will seal (sorta) against it. I used vinyl cove molding that I trimmed to fit. The pet door may not be designed to fit an exterior door, you may have to drill and use stainless screws and nuts to hold it on. Caulk well around the edge or the exterior pet door, in fact bed the edge in a bead of caulk.

Be prepared for some water in the lower section if it storms, thats why you have to caulk and seal it well, esp at the bottom. Clean out any water left there. Also be prepared for visitors you did not intend, such as possums, squirrels, other animals.

 

Has anyone used a Door Lite Router Bit with any success? A friend suggested that. One problem I see is the cost of the bit itself.

 

I'm not sure if thats a brand name or just a description. When I did a search it came back with kits for making raised panels in wood doors.

Just use a jigsaw short sheet metal blade and do one side at a time. Doubt you'll find one long enuf to cut both sides at once very well.

 

Yeah, the Door Lite router bits just make the decorative rabbetting on a wooden door for you to install glass. It won't work on a metal door. As stated figure out the location first, then drill holes and cut. Wear eye protection, please, as the shards of metal are a booger on you eyes. Cut slowly. Also, don't buy too short a blade, since your door is 1 3/4" thick, you will need a 3 or 3 1/2" blade.