Cutting Firmlok beams and 1.5 mm C purlins

So a drop saw with a cold saw blade?

I have a 2000W drop saw, but does the speed of the blade matter? (mine is not variable...)

Incidentally, I wondered if a metal band saw might be good too...

https://www.machineryhouse.com.au/Pr...stockCode=B003

OK the speed does matter.

Mine does 5000 rpm, and as far I can tell cold saws do approximately 100 times less than that.

Ok, so I got a metal cutoff saw, but my next question:

Once the beam is cut, should the end be treated with galvanising paint?

Bump... any thoughts anyone?

To confirm your suspicions, its not a good idea to put a cold cut blade into a friction saw, you end up ballistic speeds at the teeth.
A horizontal bandsaw will work too, use a fine tooth blade, lot of expense to go to though (then again, nows your chance if you're trying to justify the purchase of one to the significant other... if thats the case this work can and must only be done with a bandsaw!!!)

Once the beam is cut, should the end be treated with galvanising paint?

Clean up the ends with a file then spray with a zinc rich gold galv paint, at work Zinc-it (think its a CRC product) is the weapon of choice. If you want to keep the amount of visible cold galv down to minimum then either mask right up near the end you just cut or spray it into the lid and use a small brush to apply only onto the cut surface. Best to mask and spray a little back from the cut to seal any pits caused by the cutting. If you want to get really keen KillRust do an aluminium colour top coat that is almost identical to the galv finish your purlins will be.

Hope that helps

Originally Posted by racingtadpole

Hope that helps

Yep, sure does. thx

If its a one off job then use an angle grinder to cut them. Its cheap and does the job. If you are going to be cutting tons of them, then buy a good cold saw.