How To CUT CROSSLAPS (In Thick Lumber)

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hey everybody I'm Ethan James with the

honest carpenter comm in this video I'm

going to show you how to make cross lap

joints and thick lumber like these

pieces of 4x4 post cross laps as you can

see are an interlocking joint made by

cutting halfway through the depth of two

pieces of lumber so they can overlap one

another on an even plane in thinner

lumber these joints can be made with a

router but in thicker lumber you need a

different approach so I'm gonna show

that in a moment but first I'll mention

that I originally made cross laps like

these when I was building a wedding

Arbor for a friend you can see the Arbor

here I made it out of 4x4 cedar posts

and I'll put those decorative overhangs

and lift cuts on the ends came out

looking really great but since it was

for a wedding service I also had to be

able to break it down and set it up very

quickly so I had to engineer a few

things with the project just to make

that possible I actually wrote a short

how-to ebook about the project because

people seem to like it so much that

ebook is available on my website and on

Amazon so if you're interested in

recreating this build think about

grabbing a copy it's just a few bucks

and it has a lot of other information

about lumber selection and cutting

techniques so you get a lot out of it

but getting on with our current topic

all you really need to make deep cross

slabs like these are a square a circular

saw and a chisel to begin the process I

just decide where I want my cross lap to

sit on the pieces of lumber in this case

it's about 6 inches in from the end I

use a speed square to mark a straight

perpendicular line at this point but

instead of trying to use measurements to

layout the second line I actually like

to use the piece of stock that I'm going

to be joining I line it up by eye with

my first pencil mark then use the other

side as a guide to make my second pencil

mark and it helps to site down on the

piece from above when you do this and

you should scribe your line just a

little bit wide of the 4x4 edge these

are the perimeters of our cross lap but

now we need to set our depth so here I

do use my tape measure to find the true

center of the lumber stock which is

about an inch and 3/4 in this case and I

put a little dash right there I can then

use this line to set my circular saw

blade by eye locking it in place at this

exact depth with all these marks set

we're ready to cut

I like to make my perimeter cuts first

lining up the point of my blade tooth

with the pencil line I use my speed

square as a guide for my saw I can just

push the edge of the sole plate up

against the edge of the square this

keeps the saw perpendicular to the stock

without that much effort and I can run

my cut straight through confidently if

possible try to split your pencil mark

right up the centre takes a lot of

precision but it can be done when the

first perimeter cut is done just repeat

the same process for the other one a

quick check with the other piece of

stock shows that it will fit cleanly

inside the perimeter cuts that you've

made so now we have to remove all the

wood that's actually between these two

cuts to do this I usually clamp the

stock piece to a table for stability and

just to free up both my hands without

chaining my blade depth at all I

carefully Ben begin making a series of

cut passes through the stock spacing the

cuts about an eighth of an inch apart I

don't even use a speed square to do this

which is why my cuts start to become a

little bit angled but it doesn't really

matter the point is that I'm removing

much of the wood quickly with a strong

power tool just be careful doing it

though keep your clothing out of the way

and try to stay in to the side of your

saw a little bit in case it kicks back

it's easy to lose lose focus when you

make a bunch of repetitive cuts so pay

attention don't feel the need to rush

when all the cuts were made you have

this row of Filat strip's standing up in

place and because I've made the cuts

across the grain these strips have

almost no lateral strength to them at

all which means they can they can be

broken out with little effort I

sometimes do this with a hammer or I

just wedge a screwdriver in the last

slot and crank it over sideways and

it'll cause like a domino effect and the

pieces will generally just come out in

one big clump you can do a little bit

more cleaning by prying the filip bases

that are still standing up but to get a

smooth floor to the joint the best thing

to do is just switch switch over to a

sharp 1 inch chisel with the bevel

facing upwards

I begin to push the chisel to the uneven

material in a flat raising motion it can

help to push down on the chisel with two

fingers also as you do this to create a

bit more pressure and you can flip the

piece entirely to approach high points

from the other side as well cutting back

towards the centre to be honest I've

never been that great with a chew

carpenters don't use them nearly as much

as woodworkers do but this methods

pretty forgiving and you can use a

combination square to try to cite high

points or unevenness in the floor of the

cut where you may need to do just a

little bit more work you can also test

your cross lat fit by passing a full

piece of stock through it

if it feels too tight use your speed

square to make a salt pass along one of

the cheeks of the cut widening that side

out just a bit when the first cross lap

is clean just repeat all the steps with

the second piece measuring marks for

layout set your perimeter cuts make your

free hand passes carefully and then

break out the excess material and clean

the floor when Beau's cross laps are

done you get the satisfaction of sliding

the two pieces together for a quick test

fit if their tops don't quite line up

feel free to do a little more chisel

work on the floors at any high points

but once they do line up you're all set

if you're making structural cross laps

you can permanently join these pieces

with fasteners or adhesives or if you're

making something mobile like my arbor

use the threaded rod technique from my

ebook worked out really well and it made

it very easy to get the pieces together

and back apart again in a short amount

of time so that's how you make cross

laps and thick lumber if you have any

questions feel free to ask me down in

the comments I always try to answer them

and as always if you enjoyed the video

please hit like and subscribe below I'm

Ethan James with the honest carpenter

comm thanks for watching everybody