We are in the process of renovating our workshop somewhat and I am tearing out 30 odd years of gradually altered/grafted on/patchwork wiring and removing all the old sockets and unnecessary rubbish and taking it back to basics. We are installing founds for a new machine and afterwards are getting the floor tidied up and repainted.
Before that happens I need to cut a lot cable tracks. What is the best way to do this? I was looking at wall chasers but I've never used them and I don't know if they'd make much progress in a concrete floor, or if I'd just be better off with the stihl saw?
What size tracks and how deep, also - in concrete or screed or grano topping?
If it's concrete, being in Aberdeen you probably have granite aggregate, which is quite easy to diamond saw. Depending on how much there is you could do it with a small push-along 'pram' floor saw - you see these being used on the road a lot to cut tidy edges in roadworks. Use the smallest diameter blade you can get away with to keep the tip speed down and have maximum weight over the blade (I have loaded the front with 56lb weights before). Take passes of 25mm and keep good amounts of water on the blade. If it starts steaming or making a high-pitched whistle or if you are leaving a trail of silvery-blue granules in the wake you need more water (the silvery bits are melted blade). If you cook the blade it'll go blunt and stop cutting, the teeth will feel smooth as the diamonds have disintegrated, just remove the blade and flip it over and it will self-sharpen.
Not many saws carry double-blades - I've never seen or used one built for it - but you could easily modify one to do so using a spacer plate (which I have done). Definately, use the smallest blades you can if you do this because you'll be working to motor hard AND you want to reduce flex in the blades. Also, always cut to lines - not 'by eye'. You'll be surprised how far you can run off in a very short distance and if you're using a twin-blade setup and you run off the likelyhood is you're going to bend one blade a bit they they will stop forward progress within inches. Black marker lines are ok but hard to see once you start cutting as the water makes the concrete dark - the best marking out is done with a can of builder's line marker and a chalk line. Set out your lines with pencil marks then either spray them white then ping the halk line into the wet paint or get two people to pull a string line between marks and spray over it.
Cut your chases about square width/depth for up to about 50mm wide unless you NEED deeper, or if you're going for a wide but shallow tray then you'll have to stripe it with an extra cut or two or the breaking out will be hard going, with lots of trimming to get the tray in. Usually it's best to go 10mm deeper than the tray for the cut then set the tray on a grout bed or something (just cement and water mixed).
Main thing is - keep the blade cool with plenty of water, don't horse it into the cut. You'll need a wet vac for clearing up.
