LumberJocks

Box joint tear out

  • Advertise with us

« back to Woodworking Skill Share forum

Forum topic by otis501 posted 03-23-2011 10:05 PM 1959 views 0 times favorited 11 replies Add to Favorites Watch
View otis501's profile

otis501

21 posts in 1304 days


03-23-2011 10:05 PM

I get tear out on the back side of my box joint on the table saw even when I have a backer board.
I have a Freud dado blade and cutting ½ in oak.
What am I doing wrong or is this typical.


11 replies so far

View tenontim's profile

tenontim

2131 posts in 2400 days


#1 posted 03-23-2011 10:08 PM

I scribe the top of the cut, like laying out dovetails.

View TheDane's profile

TheDane

3784 posts in 2318 days


#2 posted 03-23-2011 11:44 PM

Do you clamp the backer board and the workpiece to the jig?

—Gerry

-- Gerry -- "I don't plan to ever really grow up ... I'm just going to learn how to act in public!"

View Gerry's profile

Gerry

253 posts in 1896 days


#3 posted 03-24-2011 12:09 AM

+1 With the Dane! For sure, the backer board should solve the issue. Scribing the board is a good idea too!

-- -Gerry, Hereford, AZ ” A really good woodworker knows how the hide his / her mistakes.”

View juniorjock's profile

juniorjock

1930 posts in 2421 days


#4 posted 03-24-2011 12:21 AM

I’ve used clear tape on the back of boards and had pretty good cuts. This may be dangerous and I just don’t know it….. (but I’m sure someone will tell me if it is). One thing for sure…. never but tape on a piece that is going to be a cut-off. Unless you want a piece of wood hitting you between the eyes….
- JJ

View Jim Finn's profile

Jim Finn

1677 posts in 1577 days


#5 posted 03-24-2011 03:46 AM

Do you think the backer board has to be as hard as the board that the box joint is being cut into?

-- In God We Trust

View gfadvm's profile

gfadvm

10874 posts in 1345 days


#6 posted 03-24-2011 05:42 AM

You must keep your workpiece tight against the backer board or youll get tear out.I usually use eighth inch ply for a backer board.I use the Freud box joint blades and have no tearout in half inch oak.If your blades are dull or dirty this might be your problem.Hope this helps.

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

View TopamaxSurvivor's profile

TopamaxSurvivor

14750 posts in 2331 days


#7 posted 03-24-2011 07:46 AM

Does the Freud box joint blades cut 1/4 slots?

-- "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View TheDane's profile

TheDane

3784 posts in 2318 days


#8 posted 03-24-2011 02:11 PM

Topa—If he has the same set I have, the Freud cuts both 1/4” and 3/8” slots.

—Gerry

-- Gerry -- "I don't plan to ever really grow up ... I'm just going to learn how to act in public!"

View TopamaxSurvivor's profile

TopamaxSurvivor

14750 posts in 2331 days


#9 posted 03-24-2011 03:04 PM

Thx Gerry, I remember that set now ;-)

-- "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View wb8nbs's profile

wb8nbs

139 posts in 1348 days


#10 posted 03-24-2011 03:35 PM

I have good luck using 1/4 inch masonite as backer (cheap). I wet the shiny side with water and a little detergent, let that soak in a couple minutes so it’s not so slippery. Have the Freud 8 inch stack dado set and because of the design of my box joint jig, I can hard clamp the the work and backer together.

http://www.flickr.com/photos/27392624@N00/sets/72157622846581829/

-- The only difference between men and boys is the price of their toys.

View otis501's profile

otis501

21 posts in 1304 days


#11 posted 03-24-2011 04:05 PM

Thanks guys, I use a 3/4 in backer board screwed to a board monted onto my miter gage to cut 1/4 slot. I tried the scribe and that made a big difference but still a little tear out, I will try the scribe and add 1/4 inch masonite to the backer board and give them both a try.

Thanks to all Otis

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com

Latest Projects | Latest Blog Entries | Latest Forum Topics

GardenTenders.com :: gardening showcase