|
|
Post by aaronkarp on Nov 28, 2021 16:50:30 GMT -5
I don't own a jointer, and want to use my MT55cc to get glue-ready edges on 6/4 hardwood boards (for tabletop glue-ups). I've seen this done on YouTube where two boards are butted up against each other and a cut is made with a track saw straight down the seam, essentially mating both boards to each other as mirror images. It seems to work great for those people, but I always end up with gappy seams.
Have you fine folks tried this technique? If so...
- What blade did you use?
- How many passes did you make?
- How did you clamp or otherwise keep the boards in place?
- Any other tips?
Thanks!
|
|
|
|
Post by lincoln on Nov 28, 2021 18:25:42 GMT -5
Only done this once, but it worked really well. Was in 38mm thick hardwood, 3 metres long. I just clamped the boards down to my bench. I'm sure I used the Mafell ripping blade, 16 tooth, though it might have been the 24 tooth. One pass, as I didn't want to introduce any steps, no matter how small they would have been. (Don't know if this would have happened).
Be careful of youtube vids - I actually watched a couple related to this a few months ago, the person claimed that he got glue ready cuts, but you could clearly see that they were nowhere near that.
|
|
|
|
Post by newuser on Nov 29, 2021 14:09:42 GMT -5
Wish I had heard of this tip before, have made do with trying to make cuts on boards on top of each other or even glued together but never had a perfect joint. How do you ensure the 1.8mm blade goes exactly along the seam?
|
|
|
|
Post by aaronkarp on Nov 29, 2021 14:28:45 GMT -5
Thanks lincoln. I'll try it with the 16t and see how it goes. I'd been using the fine tooth blade thinking that would give me a cleaner finish, but it's possible that I'm getting some deflection because the saw is working too hard. Would there be any benefit here in using a thicker blade? newuser, I guess you try and position the splinter guard about 0.9mm to the left of the seam  I was reading on the Festool forum that someone used a pencil right along the edge of both boards so they could be sure the cut had removed material from both sides. |
|
|
|
Post by lincoln on Nov 29, 2021 15:06:27 GMT -5
Seem to remember making a couple of cuts on one of the joins, because the edges weren't straight, to get them closer together. When I did it, I still had the corded MT55, haven't done it with my cordless with thinner blade.
|
|
|
|
Post by Knight Woodworks on Nov 29, 2021 17:44:42 GMT -5
I've done this many times.
The stock needs to be flat. The cutting table should be flat and fairly continuous.
If the boards are crowned, rip them before butting them. When you have a straight edge, butt them together, then clamp or screw them to the cutting table. If they move you will not get a tight joint.
Clamp the track to the lefthand board offsetting the splinter guard about half the saw kerf from the union. If the track moves, you will not get a tight joint.
What blade will depend on the material. I typically use the 24 tooth on hardwoods. Softwoods generally do well with the 32. Don't hesitate to use a courser blade as needed. If you're getting chipping you may want to tape the faces.
How many passes? As many as it takes. Sometimes it's one and done. Sometimes it takes several.
When you get an edge joint that looks good clamp it and check for flat with a straight edge. Then roll it over while in clamps. If it's flat and the underside looks tight you're good to go. If clamping produces an assembly that isn't flat and/or the underside isn't tight then your saw isn't cutting at 90*.
An easy fix may be to unclamp the assembly, roll one of the boards over such that the 'good' face is down. Butt the edges together, clamp or screw as needed. Then re-rip.
Unfasten the boards, roll, edge clamp, check the joint.
Repeat as needed until you get an edge joint and flat surface that looks good to you.
John
|
|
|
|
Post by aas on Nov 30, 2021 2:01:46 GMT -5
Pretty well covered in the reply above.
Just one thing - the whole point of doing this is that any 'error' introduced to the rail board is replicated in the right hand board - so worse case scenario, the rail is not straight - it doesn't matter, as long as the cut goes down the seam.
Likewise with saw being at 90 degrees, if it is slightly it off it makes no difference as long as the blade is cutting down the seam.
Sometimes stock is milled out of square, i.e. the sides are at 89 or 88 degrees to the face. If you have to re-cut all of the stock to 90, then join them, you could end up losing a fair bit of material - 3 or 4 mm each side of a board over several boards soon adds up.
As long as the boards you are joining are both 'leaning' the same way, you can set the saw to 1 or 2 degrees and join like this.
Also, the most important thing with regards to the blade is that the saw should not 'force' through the cut - this can cause micro vibrations of the blade.
You see this sometimes on the face of an edge you have cut as an arc the size of the teeth. When the boards are butted up to each other, you in effect double the error as the vibration will be left and right, so they will always line up in the join and be twice as visible.
It's about finding the right balance between cut finish with the number of teeth, and the speed you push the saw through the cut - you don't want to go too slow either (risk of burning, etc).
Asides from that - all the usual - don't clamp the rail too tight as it can bend; snug the saw up to the rail so there is no slop but not too tight you can't push it; if you need to cut in 2 passes, don't use the lever for a pre-cut - set the depth to 1/2 of the cut, then re-cut at full depth; if you're getting chipping and the tape isn't working, set the depth to about 6mm for the first cut - this will be past the step of the pre-cut lever so the main cut will line up, but the blade cut angle will be shallower.
Let us know how you get on.
|
|
|
|
Post by MrToolJunkie on Dec 1, 2021 0:42:55 GMT -5
As stated above. Honestly, I rarely use this technique and just rip each side separately. I seem to get much better results doing it this way for whatever reason.
|
|
|
|
Post by aas on Dec 1, 2021 3:24:09 GMT -5
As stated above. Honestly, I rarely use this technique and just rip each side separately. I seem to get much better results doing it this way for whatever reason. Me too, I find cutting separately gives consistent, repeatable results. |
|
|
|
Post by aaronkarp on Feb 23, 2023 16:57:23 GMT -5
For posterity, I wanted to follow up on my original post and say that I've been successfully using this method and getting jointer-quality glue joints. I just made a white oak tabletop out of six long boards, and used my MT55cc on the edges. I did not do multiple boards simultaneously, I simply adhered each board to the edge of my workbench using double sided tape, with the long edge sticking off an inch or so. Then I clamped my track to the board using the clamp slot that is closest to the splinter guard (this was essential, I found), and used the lowest tooth count blade I had. Went slow. I was shocked at how well the boards lined up. Glue lines are (nearly) imperceptible for all boards along the full 54" length. (Image below is super zoomed in.) Love this saw.  |
|
|
|
Post by aas on Feb 24, 2023 1:31:57 GMT -5
Nice result. What blade are you using?
|
|
|
|
Post by Knight Woodworks on Feb 24, 2023 9:00:02 GMT -5
Nice. Glad it worked out.
John
|
|
I was reading on the Festool forum that someone used a pencil right along the edge of both boards so they could be sure the cut had removed material from both sides.