LumberJocks

Milling

  • Advertise with us

« back to Wood & Lumber forum

Forum topic by mike123789 posted 02-20-2017 09:26 PM 676 views 0 times favorited 10 replies Add to Favorites Watch
View mike123789's profile

mike123789

11 posts in 300 days


02-20-2017 09:26 PM

Topic tags/keywords: jointer milling rough lumber cutting board bulge

Hi Guys,

Quick question. I am making end grain cutting boards. I am taking my rough lumber and starting at the jointer and running one face and side to get them flat. then I use my planer for the other face and the table saw for the last edge. my square shows all angles square and my calipers show all sides parallel. however, after my first glue up, I flatten the board again, then I make my 1.5 inch cuts and rotate. and the center of each of the “rows” is larger in the center. resulting in another trip to the jointer and planer for each piece which loses material. I have milled a lot of lumber but the last two boards I have made have this happen. I thought it may be my process but with all measurements and readings showing that they are properly milled I can not come to a conclusion as to why this is occurring. any help would be greatly appreciated.


10 replies so far

View Lazyman's profile

Lazyman

1508 posts in 1227 days


#1 posted 02-21-2017 01:47 AM

To make sure that we understand the problem, are you saying that you glue up strips that are flat with parallel sides, joint and plane the glued up board to ensure that it is flat a flat and parallel and then cross cut them into strips (the rows) ? Are you saying that these cross cut rows are thicker in the middle of their length or are you saying that when you turn them end grain up, they are thicker in the middle of their lengths?

Or did I completely misunderstand?

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View JBrow's profile

JBrow

1275 posts in 759 days


#2 posted 02-21-2017 02:46 AM

mike123789,

It sounds like you have taken great care to produce the first glue-up. You did not specifically say, but I assume that when the first glue-up was flattened, the faces remained parallel to one another. Therefore I wonder whether the first glue-up absorbed or lost moisture on one face versus on the other face. If the first glue-up was relatively thick, the change in moisture could go unnoticed until the strips are cut off the first glue-up. With less wood to restrain movement, the strips could bow. If this happened, then clamping pressure could be enough to overcome the bowing if the bow on one strip is opposite the bow of the other strip. If the bows run parallel, then the assembled strips could appear wider in the center than on the edges.

I would think that if the first glue-up were set on a solid surface for a few hours, enough moisture could enter or leave the wood on the surface exposed to the air and build up stress in the first glue-up. I do not where you are located, but the weather has been atypical here in Ohio, with low humidity and cold temperatures one day followed by a day of higher humidity brought on by higher temperatures. If your weather has been crazy wild, then perhaps this explains why your two most recent cutting boards have been problematic.

If the top and bottom faces of the first glue-up were not kept parallel to one another when flattened, then perhaps this unevenness accounts for the problem.

View mike123789's profile

mike123789

11 posts in 300 days


#3 posted 02-21-2017 04:18 PM

Nathan,

After i cut the first glue up and turn them to expose the end grain. That is when I notice the bulge in the center. tonight I will take a picture of one to better explain.

View mike123789's profile

mike123789

11 posts in 300 days


#4 posted 02-22-2017 01:49 PM

here is a board i never fixed. I used soft wood on this one to practice my milling. The gaps aren’t as pronounced as they were a month ago but it gives you an idea. pushing the wood together on either side produces this kind of gaping. I tried to clamp it but the gap was too wide and resulted in breakage.

View mike123789's profile

mike123789

11 posts in 300 days


#5 posted 02-22-2017 01:51 PM

this one had the same issue but using the jointer and planer on each piece before the final glue up fixed the problem

View generic's profile

generic

105 posts in 1438 days


#6 posted 02-22-2017 02:34 PM

When planing did you tighten the thickness locks on the planer? I had what appears to be the same issue. I found it was due to me being lazy and not locking the height on my planer. in my case the side without the adjustment knob would flex ever so slightly and the board would be ever so slightly thicker on one side. Normally you would never notice it, but when stacking flipped cuts up, it shows. The next board I was more careful and tightened the thickness locks and the problem went away.

View mike123789's profile

mike123789

11 posts in 300 days


#7 posted 02-22-2017 03:12 PM

yes. I lock it during each pass. I use the rigid 13” planer

View generic's profile

generic

105 posts in 1438 days


#8 posted 02-22-2017 03:38 PM

After flattening your first glue up and before cutting the strips to turn for the end grain, did you measure the board thickness on each side and in the middle? If your planer has become out of adjustment, it would show up on the wide board and cause what you are experiencing. when planing and checking narrow boards, the difference could be too small to notice.

View mike123789's profile

mike123789

11 posts in 300 days


#9 posted 02-22-2017 04:26 PM

yes. I checked the planer. the board was parallel all the way across. I used my calipers and the only variance was minimal. 1.645 on one side and 1.648 on the other over a 22 inch span.

View Lazyman's profile

Lazyman

1508 posts in 1227 days


#10 posted 02-23-2017 01:41 AM

Are you ripping those strips with the fence or cross cutting with sled or miter guage? Is it possible that the blade is not parallel to the miter slot or the fence isn’t parallel to the blade? You might want to try doing s 5 cut test to see how accurately it is setup.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

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