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is it the quarter sawn Oak?

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Forum topic by drcodfish posted 12-02-2015 07:49 PM 840 views 0 times favorited 17 replies Add to Favorites Watch
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drcodfish

115 posts in 412 days


12-02-2015 07:49 PM

I’ve finished my bench ( glad I did it) and now I am back to making boxes.

I have made several boxes with box or finger joints using an Incra I-Box jig on my Grizzly table saw. I started using 1” poplar and once I had gotten most of the major mistakes out of the way, I stepped up to clear, straight grain 1” Hemlock. I considered these practice pieces getting ready for something a little nicer. Not show quality but I was happy with what I learned and how I progressed through the several ‘test’ boxes I finished.

I have just started my next box project using 1/2” quarter sawn white oak and I’m having an unanticipated problem: I am getting serious ‘reverse’ tear out with the I box jig. By that I mean the cut joints are leaving ragged edges, something I didn’t experience previously. The only thing which has changed is that I am now using thinner stock (1/2” vs 1”) and it is quarter sawn oak. these joints are made on the end grain of the stock. Any idea why I am having this problem? Do you think it is the fact that the wood I am now using is quarter sawn?

My dado set is not the greatest but it cut fine previously, and I have taken pains to set the jig up according to the instructions that came with it. I know I could probably back up the stock with a sacrificial piece and will do so if that is the last resort but hope some one out there knows a better way to solve this problem. I would attach a picture but my camera’s resolution is too high.

I will charge up the battery on my old camera and see if I can get a pic with it that will work here. In the meantime, who’s got the easy button on this problem?

-- Dr C


17 replies so far

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TheFridge

5764 posts in 946 days


#1 posted 12-02-2015 07:55 PM

Do you have a sacrificial board behind it?

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

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drcodfish

115 posts in 412 days


#2 posted 12-02-2015 08:11 PM

No sacrificial piece. I mentioned this in the original post and I know I could go that route but am looking for another solution first before chewing up a lot of stock.

Thanks for the suggestion though, and I will give that a try if I have to.

-- Dr C

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HokieKen

1735 posts in 598 days


#3 posted 12-02-2015 08:27 PM

I’ve never worked Hemlock but I know that white oak is significantly harder than poplar. I typically see more tearout with harder woods but with smaller “splintering” than soft woods. White oak is also pretty open grained so that could contribute as well. I’m not sure if QS would have anything to do with it or not. One way to see is to make a few test cuts on some oak scrap that isn’t quarter sawn.

-- Kenny, SW VA, Go Hokies!!!

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drcodfish

115 posts in 412 days


#4 posted 12-02-2015 08:32 PM

Western Hemlock is pretty soft, softer than poplar I think. It is a local (native) wood here in the pacific northwest.

The Oak

Western Hemlock by comparison

-- Dr C

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drcodfish

115 posts in 412 days


#5 posted 12-02-2015 09:37 PM

Here is the cut made in 1/2” plain sawn red oak

and the ‘front’ side of the board shown above

-- Dr C

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pintodeluxe

4852 posts in 2273 days


#6 posted 12-02-2015 10:20 PM

You need a sacrificial board anytime you do box joints. Cutting boards on end, as one does with any box joint jig, increases the chance of chipout. That is pretty severe though. Slow down your feed rate, and only take one pass over the dado set (don’t pull the workpiece back over the blade).

The main thing is the backer board. The very best dado sets will improve cut quality, but I haven’t found that necessary.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

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rwe2156

2189 posts in 941 days


#7 posted 12-02-2015 10:27 PM

Dittos on what pinto ^ said.

Just slide the backer board on over and hit it in a fresh place you’ll be good to go.

Also remember oak is one of the splinteringist (is that a word?) wood there is.

-- Everything is a prototype thats why its one of a kind!!

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Jim Jakosh

17118 posts in 2565 days


#8 posted 12-02-2015 10:38 PM

The oak is real open grain. It tears out in the lathe too if you are cutting dry stock. I’d put a board behind it to support the wood being cut out. That should stop it.

Climb cutting prevents this, but I don’t think you want climb cut that deep of a cut!. I climb cut all wood on the mill to prevent tear out.

Jim

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

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AandCstyle

2561 posts in 1717 days


#9 posted 12-02-2015 11:50 PM

Dull blades also increase tear out.

-- Art

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HokieKen

1735 posts in 598 days


#10 posted 12-03-2015 04:48 PM

From the pics, I’d say the QS definitely exhibits more tearout. I’d have to agree with everyone else that backing up the cut should eliminate your problems. Like Art said too, check to make sure your blade’s sharp.

If you just really don’t want to back the cut for some reason, you can try taping the backside of the board with painters tape before cutting. I’ve done it on plywood and it worked well. Not sure if it’ll work for the QS oak but you could give it a shot.

-- Kenny, SW VA, Go Hokies!!!

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drcodfish

115 posts in 412 days


#11 posted 12-03-2015 08:26 PM

”If you just really don’t want to back the cut for some reason, you can try taping the backside of the board with painters tape before cutting. I’ve done it on plywood and it worked well. Not sure if it’ll work for the QS oak but you could give it a shot.”

I didn’t mean to give the impression that I am unwilling to back up these cuts. I was just hoping someone would point out that I had gizmo A incorrectly calibrated to interface with doohickey B. I am convinced by the dearth of responses that backing up the cuts is the thing to do. I’ll give it a try this weekend and report the results.

There were several mentions of dull dado blades. Exposing my newbiness here, how can I tell if my blades are dull? They should not be, the set has seen very light use in the year that I have owned it (maybe half a dozen boxes, each with 4 sides of course.)

Thanks to all for weighing in.

-- Dr C

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HokieKen

1735 posts in 598 days


#12 posted 12-03-2015 08:47 PM

Your blades shouldn’t be dull, especially if they’re carbide tipped which I’m sure they are. Best way to tell is if you start seeing more tearout than usual or if your motor starts bogging down. You can also look and make sure you have a sharp corner all the way across the teeth. Sometimes a single chipped tooth on the blade can cause tearout but it looks like your cut is pretty uniform across, so I wouldn’t imagine it could be a bad tooth on a single cutter.

-- Kenny, SW VA, Go Hokies!!!

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drcodfish

115 posts in 412 days


#13 posted 12-03-2015 11:18 PM

Thanks for the tip Kenny. Using the dado on fir, hemlock and other local soft woods I get almost no tear out so I assume sharpness is not a problem. One thing that does bug me though is that when I cut a wide dado, 1/2” or better I don’t get a nice smooth flat bottom to the cut. It is easy to see the different depth of cuts of the outside and inner cutters. Is this the difference between a cheap dado set and those very expensive high quality sets? I paid about $50.00 for the set I have on sale at the Big Orange Hardware Store, but I have seen those Freud sets for $275.00 in the wood worker boutiques and can’t help but wonder if they are 5 times better. I am not averse to spending $$$ for quality tools but I am not a brand name addict.

-- Dr C

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drcodfish

115 posts in 412 days


#14 posted 12-04-2015 06:57 PM

sacrifice pays off.

The front of the cut with a piece of 13/64 plywood I use to back up the cut:

And here is the back side of both of these pieces:

It may not be apparent but this scrap of 1/2” oak was cupped a bit.

Thanks all for your in put. I can now proceed to ‘boxing for Christmas’.

-- Dr C

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drcodfish

115 posts in 412 days


#15 posted 12-04-2015 10:01 PM

Mo Beddah!:

Now for a bottom and a lid.

-- Dr C

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