Help me find the best way to do an inverted T shape cut in 2.4m oak sleeper

[JohnMi]

Hi guys,

Please have a look at the pictures. I want to cut out an inverted T shaped section in an oak sleeper so it can slide on top of an existing concrete post. You can see the shape i want to cut out drawn on the side of the wood. It is 6ft or 1.8m in length the section that i want to cut out 5.5cm wide 8 cm deep and widening to 9.5 cm between the 5th and the 8th cm . What would you say be the best way to cut out that shape

 

[hlvd]

Give up, as I doubt you’ll be able to do that.

Rip it in half, cut the necessary half channel and glue back together.

Or just cut a groove the width of the T and machine infill strips to neck the groove.

Why do you need to do this?

 

[Bingy man]

Not a easy task especially in oak , imo I would simplify what you want to achieve by making up your profile in sections of hardwood to create the rebate your after , if it has to be done as per you photo then I would use a table saw or c/saw to cut either side of the straight section , then a straight cutter to route the waste in say 3-4 passes then a suitable rebate cutter either side of the straight section to create your profile. 1/2 “ router and 1/2 “ diameter cutters - a test run in soft wood will help you get your set up spot on . Good luck btw cheap router bits will probably struggle..

 

[Peri]

It's a common task in metal work - put a channel down the middle with a straight cutter, then use a T slot cutter (or wing cutter) to open up the two side channels.

You might be able to do the same if you can find a long t-slot cutter for the router (that you can make several passes at various heights with)...if such a thing exists !

 

[macca]

Rip it neatly down the middle with your tracksaw that hopefully accompanies the track pictured, then you should have a fairly simple task of removing the waste you need with the added bonus of being able to see anywhere it gets tight without waving a 1.8M length of oak another 1.8m in the air. I should hope the first rip should be neat enough that the resulting glue joint would be pretty passable for the garden fence!

With that said sleepers aren't the best behaved timbers and you are removing a lot of material down the middle of the chunk of the wood thats going to be out in the elements, I would be surprised if it stays neatly round the post the way you are picturing it.

Those posts usually have holes in the rebates for attaching timbers to affix panels and/crossmembers so maybe you could look to add in some cheaper treated timber to the rebated section of concrete post, cut a rebate from the back of your sleeper that covers post and said timbers and use the bolt holes to bolt the whole lot together and hopefully stop the oak moving soo much and save the hassle of cutting a T in the oak.

 

[porker]

As above I think taking out the main "slot" is not too difficult with a tracksaw or circular saw (assuming you have enough depth on the blade). Multiple parallel passes and remove waste with a framing chisel. The problem is the "ears" as I don't think there is a router bit big enough to do that.
If you really don't want to cut the beam in half and rejoin as suggested maybe you could cut the "slot" full width as described above and then fix in two strips in the slot to make the "ears" again. You could use a different wood as they could not be seen.

 

[Adam W.]

My advice is to give up and drink gin and tonic.

 

[TRITON]

You can get an extension for a router bit, but i dont know if you could get the full width cutting the 'wings' or the slot. You'd need to do your sums and know exactly how to go about it. Saturday night so im not working it out
eg
https://trenddirectuk.com/trend-ce-...MItrXQseyP-QIVDLbtCh0EcgcSEAQYBCABEgLO0PD_BwE

 

[Lorenzl]

If you can find a way to mount it you could use a "side and face cutter" although you need some tool that was slower rotating.

 

[Lefley]

Hi guys,

Please have a look at the pictures. I want to cut out an inverted T shaped section in an oak sleeper so it can slide on top of an existing concrete post. You can see the shape i want to cut out drawn on the side of the wood. It is 6ft or 1.8m in length the section that i want to cut out 5.5cm wide 8 cm deep and widening to 9.5 cm between the 5th and the 8th cm . What would you say be the best way to cut out that shape

Thinking outside the box. Cut the concrete! I would do a couple of dado cuts in the wood at say 20 degrees each way to create a dovetail cut per say that is a little cut into on the bottom. Then with a concrete saw cut the two sides off the concrete beam to form a dovetail. Then slide together!

 

[Droogs]

I would just cut a straight sided rebatedown the middle of the sleeper that is as wide as needed to fit around the post. Then once the sleeper is around the post,cut packers for fitting into the waist of the I beam and bang them in slathered in epoxy and secure with a few screws until it sets.

 

[dickm]

It's a common task in metal work - put a channel down the middle with a straight cutter, then use a T slot cutter (or wing cutter) to open up the two side channels.

You might be able to do the same if you can find a long t-slot cutter for the router (that you can make several passes at various heights with)...if such a thing exists !


View attachment 140182

Er - have you looked at the sizes involved? Even if it were possible to buy a suitably sized router cutter, which I doubt, you'd need the arms of a gorilla to control the router!

 

[Bod]

Hi guys,

Please have a look at the pictures. I want to cut out an inverted T shaped section in an oak sleeper so it can slide on top of an existing concrete post. You can see the shape i want to cut out drawn on the side of the wood. It is 6ft or 1.8m in length the section that i want to cut out 5.5cm wide 8 cm deep and widening to 9.5 cm between the 5th and the 8th cm . What would you say be the best way to cut out that shape

Cut a triangle instead of a "T".
There will be wasted space inside, which could/will lead to the wood moving to a different shape, so do get the post in place before cutting the wood, then fit as quickly as possible, within minutes of finishing the cuts.

Bod

 

[pip1954]

Why not cut the face of right across then you can cut the middle out then last of all cut out the two corners all done on a table saw nice and safe once cut out glue pieces back together can even screw from the back because the glue joints are down the sides not so obvious and you get the waste as a piece of timber

 

[Adam W.]

@JohnMi ....Is your saw big enough and powerful enough to make all these different cuts that are being suggested?

A little plunge saw will struggle and you'll probably kill it before you're finished. To do any meaningful cutting on this oak you need a big circular saw with a large powerful motor and ideally a 4" cut or larger and not an MDF saw.

 

[Thingybob]

Sit down and think it out is it worth all this hassel what am i trying to achieve and would it look just as good boxing in the concrete post with planking and job done and move on to next project

 

[Jones]

What you are suggesting is not going to be possible. Sawing in half then cutting/routing the shape then reguleing is a lot of work for big tools and movement may mean it doesn't work as well as you hope.
So you need to think of a plan B. Could you cut the concrete post down to an 18" stub, cut a recess in the oak to sit over the stub and bolt through? You would need to plant on battens to hold a fence panel if there is one .

 

[Thingybob]

John a bit more information as to your end goal would help with the best result for ideas from members here

 

[Myfordman]

If what you are wanting to end up with is a vertical Oak post supported by a concreted on in the ground, then I would use a spur post instead which has a rectangular section and thus much easier to cut out in the oak. If you wanted to hide the concrete completely then a second cover piece of oak could be used.

 

[Against_The_Grain]

It’s not wholly impossible to do, it could be done on a spindle moulder or pattern mill with a flush top block and spindle combination but it’s quite an advanced operation in terms of skill and very few modern joinery workshops will be kitted out to do it or even willing to do it.

Even if you could do it, there will be a challenge with wood movement, you will need to slide the piece on the post immediately otherwise it will close up and you won’t be able to get it onto the post.