[vorkosigan1]

Hi, new guy and very occasional woodworker here.

I bought some radiator covers made from 3/4" MDF. They have slots on the front, like this one: https://www.lowes.com/pd/Fichman-Furniture-39-5-in-x-28-75-in-Unfinished-Radiator-Cover/1000789014

I want to put slots in the top, to match the slots on the front (and then I'll paint the whole thing).

I assumed I could build some kind of track or template, clamp it to the top, and then use a plunge router to cut those slots, sliding the router along the track, and then move the track for each new slot (maybe 3 or 4 slots on each top). From what I've read here and elsewhere, MDF is pretty tough to cut, so I'd want at least a 1.5 or 2.25 HP router, and carbide bits.

However, some friends who have used routers are suggesting that I instead cut the slots with a jigsaw, and just use the router for the ends of each slot. That sounds like a lot more work, but I've never used a router before, so I'm hoping y'all can give me some advice here.

Thanks in advance!

 

[sunnybob]

Routers are much better at cutting a finished edge than digging a trench, especially in mdf.
Listen to your friend and remove most of the waste first.

 

[harrysin]

Routers are much better at cutting a finished edge than digging a trench, especially in mdf.
Listen to your friend and remove most of the waste first.

Hi, new guy and very occasional woodworker here.

I bought some radiator covers made from 3/4" MDF. They have slots on the front, like this one: https://www.lowes.com/pd/Fichman-Furniture-39-5-in-x-28-75-in-Unfinished-Radiator-Cover/1000789014

I want to put slots in the top, to match the slots on the front (and then I'll paint the whole thing).

I assumed I could build some kind of track or template, clamp it to the top, and then use a plunge router to cut those slots, sliding the router along the track, and then move the track for each new slot (maybe 3 or 4 slots on each top). From what I've read here and elsewhere, MDF is pretty tough to cut, so I'd want at least a 1.5 or 2.25 HP router, and carbide bits.

However, some friends who have used routers are suggesting that I instead cut the slots with a jigsaw, and just use the router for the ends of each slot. That sounds like a lot more work, but I've never used a router before, so I'm hoping y'all can give me some advice here.

Thanks in advance!

This PDF shows how I rout slots, the second method shown only requires the addition of spacers between each slot. The best type of bit is what's known as a plunge bit which has an extra blade at the bottom but a sharp standard bit still does a perfect job through MDF but moving the router backwards and forward an inch or so prevents initial burning.

 

[mgmine]

Whatever you do, do it outside even if it's cold out there. You will get an incredible amount of dust.

 

[Rebelwork Woodworking]

 

[harrysin]

View attachment 397536

I hope you don't mind.

 

[TenGees]

Usually you would want to make several passes to route through 3/4". You can use the turret depth-stops on most plunge routers to do that. The dust from MDF is pretty nasty. So bad that many prefer not to use it. If you cut near the lines with a jigsaw first and then route to finish, you'll be turning much less of the MDF into dust and you'd be able to route in one pass to clean up the cut.

 

[roxanne562001]

Welcome to the forum.
I am with Paul on this MDF is very dusty where a dust mask. I use MDF a lot in my toy making. It cuts easy with a jigsaw. Then just clean up the slots / edges with the router.

 

[ScottyDBQ]

You might consider drawing out the locations of the slots on the tops, drilling a hole at each end of your laid out slots and then using a jigsaw to cut out the bulk of the slot. Leave 1/8 to 1/16 of an inch between your cut and the finished line for the slots. This will let you remove about 90+% of the MDF that you have to get rid of. You can then use a router to bring the slot to final dimensions. This should also leave you with relatively well finished sides to the slots. You can use a straight edge like Rebelwork posted or a ski setup like harrysin posted to get a straight cut with the router. Since most of the material was removed by the jig saw, there's much less work for the router. And heed the comments about the dust and doing this outside. Use the best dust mask you can -- not just a paper mask. If you do it indoors, remember the dust is very fine and will be floating around your shop and into your lungs for quite a while. And try this technique on a scrap board before going to your workpiece.

 

[DesertRatTom]

Scotty's suggestion is how I'd do it. Drill holes first, use your jigsaw to cut most of space between the holes, then using a straight edge to guide your router with a straight or trim bit smaller than the hole. line the bearing up with your straight edge and clean up the cut. Straight edge can be a straight piece wood clamped in place.

Draw a line from the top and bottom of the holes to the opposite hole, then line your straight edge with that line. The bearing on the bit will follow the straight edge and give you a nice, finished cut. MDF is truly awful stuff. Wear a mask, and it is really hard on bits and blades. You want a trim bit with a top mounted bearing. It should be a little longer than the thickness of the mdf. I always have to think twice about which is the top and bottom on bearings, so here's a diagram.

 

[old55]

Welcome to the forum @vorkosigan1