Cutting out for Newell post in Balau - best way????

harryharris · 27 Apr 2008

Hi, I am coming to the end of building a deck in Yellow Balau, the newell posts are to be bolted to the outside of the deck frame. The handrail is in an L shape so on one side the post will attach at the ends of the deck boards and at the other side the will go against one run (length ways) of deck board. I need to cut out for the newell posts, approx 80mm wide by approx 30 - 50mm deep, I want neat square cuts.

My concerns are that balau seems to be a bit "fiberous" when cutting and achieving a neat squre cut, do not want to raduis the corners too much ie by drillng and cutting straingts with jig saw. Any advice / ideas offered welcome, my thoughts are to invest in a router (which at some point I want to buy anyway) and fabricating my own jig from plastic etc. However Im concerned the router will not achieve a neat finish because of the properties of the wood - though the fact it is moulded to form deck boards with grooves suggests otherwise?

OPJ · 27 Apr 2008

The router would be a very good option or you could possibly use a sliding compound mitre saw with a depth-stop, if you have access to one.

If you're worried about any tearout with the grain (which generally will only occur when cutting across the grain), you could temporarily fix some scraps of MDF or timber either side of the joint while you rout it. That would stop the grain from breaking out on either side.

If you can't clamp these scraps in place without the clamps interfering with the jig you make, then you could try double-sided tape or even stick them on temporarily with a couple of small dabs of hot-melt glue from a glue gun.

harryharris · 27 Apr 2008

Thanks for the reply, I have a sliding compound mitre saw but I could not work out how to achieve the cut?

OPJ · 27 Apr 2008

Sorry, I think I mis-read your first post. I don't see how you could cut that kind of housing with anything other than a router either.

Gary M · 27 Apr 2008

Hi Harry,
Assuming the decking is already laid.
Mark out your cut out, cut the two sides (across the profile) with a fine tooth saw say 10 teeth per inch . Start again at one outside point and cut across to the opposite inside corner at 45 degrees. that piece should then fall out. Use a coping saw to then cut across from one inside corner to the other.
Clean up with a sharp chisel if needed.
You can use a downcutting jigsaw blade for this as well as its not that deep a cut this would probably be a lot easier than a coping saw.
You could use a router and jig, but it seems like a lot of work.
Bear in mind that if the opening is too tight it will rub on the newel post and squeak when you walk past it as it will swell and contract with the differing weather conditions.
HTH,
Gary.

harryharris · 27 Apr 2008

Thanks for the advice - both topics. Continuing on the Balau decking theme, you guys obviously have some first hand experiance of the stuff, is it normal for it to expand so much?

I laid most of the boards towards the end of last summer so they have experianced their first winter, the gaps between the boards has disappeared in most sections of the deck. I began to think I had mounted them too close but having checked my photos soon after installation Im convinced I allowed enough space between boards - approx 6mm (I used plastic spacers to set the gaps). Will the boards shrink back in the dryer/warmer (hopefully) summer weather and will applying a deck oil/coating reduce the expansion next winter?