Domino and KAPEX used to remove knots in boards

[TomGadwa1]

As a proud owner of a HAMMER A3 31 combo unit I always strive to adhere to the companies wishes regard the use of the unit. I am building a frame for the mirror in my bathroom and have a board that I cut up into some rail and stile type pieces. To my dismay some of the pieces had knots within them. HAMMER prohibits running material with knots through their units as it can damage cutters due to the differing and much denser nature that a knot in wood reveals. Thus my dilemma. What does one do with the knots. My solution is to take them out! Using my KAPEX I cut on either side of the knots that were in my boards. Then I used dominoes to reconnect the board pieces back together. This way the offending knots are gone and I can now face plane and thickness my boards without any issues relating to knots.
http://www.youtube.com/watch?feature=player_detailpage&v=KLtGT_RrFZk
Once again the Domino saves some wood!!

 

[wrightwoodwork]

What a load of rubbish, my mate has a hammer A3 31 and I've put through material with knots and it does it no harm only just blunts the cutters slightly. Also as long as the blades are sharp and you only take about a 1mm pass then you will not get any problems. Don't try to take off the maximum that you can just a little at a time and you will also get a cleaner finish. If you still insist on removing the knots and patching I know that lamello make machines especially for the task but is quiet expensive and honestly unnessary

 

[jonny round boy]

HAMMER prohibits running material with knots through their units as it can damage cutters due to the differing and much denser nature that a knot in wood reveals.

Really? Sorry, but that's ridiculous. Timber contains knots, you can't avoid that fact.

 

[festoolviking]

Hi

I got no opinion on the Hammer. Just want to say that the video was nicely made. With a fixed camera and the sound-effects. I liked that [smile]

Festoolviking

 

[GarryMartin]

The knots and colour in those pieces were beautiful and added such character. If they were stable, why remove them on a piece such as a mirror?  [sad]

[EDIT] Curiosity got the better of me and I downloaded the A3-31 manual and can't find any reference to knots other than jointing issues. I wonder if TomGadwa1 could advise on where the instructions to remove knots came from as it doesn't appear to be the manual?

 

[woodguy7]

3 1/2 minutes of my life i won't get back  [mad]
I too think that is nonsense.  I have a Felder planer/thicknesser & have never had an issue dressing timber with knots.  I disagree with your comment that the grain still looks ok !  It dose not.  It draws your eye straight away & not in a good way.  You are also weakening the board.  As far as I'm concerned the less joins in a board the better.

Sorry but its my thoughts on it.

 

[Mikeclewlow]

[eek]
Not seen that or heard that in the 24 years I've been in the trade
End grain to end grain joint will be weak
Not surprised of it didn't cause a stress fracture when it went through the machine.  Is this a testament to hammer quality ??

 

[Birdhunter]

My planer has carbide helical cutters and would have no problem with smoothly cutting through knots. However, I would Super Glue the knots before running them through any power tool. My concern would be the knots coming loose and either jamming the machine or becoming high speed projectiles.

For the piece being constructed, I'd guess the end-to-end butt joint with double Dominos is adequately strong. I would not use that jointing for a board bearing much stress.

The OP's idea would word to make a board longer, especially if the piece is to be painted.

The photography is innovative.

 

[TomGadwa1]

The material is being used to picture frame a mirror. Therefore there will be no stress on the end grain joint. Birdhunter has a good point about the possibility of the knot becoming a projectile. Looking at the end results one of the seams appears quite natural and the other one is not too bad either. If I could get better wood I would. But in this case I decided to make the best out of the raw material that I thought I could. The other idea about filling the knots may cause issues when being milled and could accelerate the need for maintenance on the machine. And no I am not questioning HAMMER quality but trying to respect what is a substantial investment for me!

 

[Timtool]

Don't worry Tom, it is probably some form of legal talk to protect themselves.
Knots are basically end grain, it is harder on the blades and wears them faster, when i lay out my parts on the boards i try to leave out the knots but if there is one in the part i will just pass it through unless the knot is loose.

I would have much less problems with planing knots than working with parts that were end-grain assembled!

 

[Deansocial]

Epic fail