Which saw blade for cutting aluminium and plywood?

[city17]

I'm working on a table saw sled which has two aluminium extrusions as a fence. Now I'm at the point where I can make the first cut through the sled, but I'm not sure what type of blade to use, since it would be cutting both aluminium and plywood at the same time.

I've only got a standard 254 mm 40 x alternating tooth blade at the moment. Would that blade be able to cut through the aluminium (moving slowly)?

And if not, what would be a good alternative? I'm considering an 80-tooth aluminium cutting blade, or a 60-tooth wood blade with alternating teeth.

 

[Cabinetman]

I would say it will be absolutely fine, I’ve cut worse than that and the blade hasn’t been affected at all, as you say, take it slow through the aluminium sections. Ian

 

[TheTiddles]

Slow cut, make sure everything is held tight as the teeth on an aluminium blade will be less aggressive, but should be fine.
Get a new one soon after if you want a good finish again

 

[city17]

Thanks @Cabinetman and @TheTiddles. I took it slow and it cut the aluminium with no problems whatsoever.

The sled is almost finished now, just a few tweaks and a flip stop to add. The block in the middle works like a mini-Fritz and Franz jig, makes it easy to rip thin strips.

Any tips on making the runners a bit more smooth? I'm afraid that if I plane/sand them the fit will become too loose. Any good results with paraffin or similar lubricants? The runners are made of oak.

 

[Austin Branson]

Beeswax.

 

[TheTiddles]

The other thing you need to do is put a guard over the top and have you got a stop so you don’t push too far and have exposed blade coming out the back fence?

 

[city17]

The other thing you need to do is put a guard over the top and have you got a stop so you don’t push too far and have exposed blade coming out the back fence?

Forgot to mention the top guard, that's also on my to do list. I'll also add a block to the front where the blade comes out to prevent it from being exposed (unless I push it really far). Haven't thought about a stop though, how would you implement that?