SB: Re: metal roofs

[Rob Tom <ArchiLogic@yahoo.ca>]

8/30/2002 11:44:59 AM, "Rey Arbolay" <TXH2344@mynra.com> 
wrote:

>About cutting the metal. I originally bought the recomended 
>carbide tipped blade designed for this purpose. Is is useless. The 
>blade skips, runs, overheats the metal (even if you cut really 
>slow) and is loud as hell. Then a friend recomended the metal cut 
>off blades they sell in packs of 10 at your local hardware stores. 

Rey ;

The blade to use is an old plywood blade, mounted backwards in the 
saw. (ie teeth pointing down, in a handheld saw).

The blade will last forever and doesn't spit abrasive grit all over 
everything. 

That being said, the problem with using any sort of blade in a circular 
saw is that :

 (1) It burns off the coating on the steel (whether it be paint or  
      galvanising ) so that there is unprotected metal which will be 
      susceptible to rust.

 (2) It leaves a rough edge which looks like $#!+ and will catch & 
       tear anything that rubs up against it (whether it be clothing or 
       flesh)

(3) The spray of  sparks flying off of the blade leaves smalll metal 
     particles which will leave rust spots on any steel upon which it 
     lands if not washed off.

Problems #1 & #2 can be dealt with by 
    (a)  Trimming the sawcut using 10" sheet metal shears 
         (aka tinsnips) but NOT aviation snips which make a %$@$ 
          mess) and painting the cut or
    (b) Burying the cut edge beneath a lap or flashing or
    (c) Folding the sawcut edge under, leaving a folded edge exposed 
         to any weathering
     
To avoid dangerous kickback and binding, both sides of the cut need 
to be supported. (ie a minimum of two sticks on each side of the cut).

To avoid marring finished surfaces,  one should cut from the backside 
of the sheet, using something like duct tape on the table of the saw to 
avoid metal-on-metal rubbing.

       
 ~~~*~~~
 Rob Tom
 Kanata, Ontario, Canada
<ArchiLogic@CHAFFyahoo.ca>
(winnow the "CHAFF" spamguard from my edress in your reply)

 Please visit http://www.the HungerSite.com daily




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