Author Topic: Longtime Lurker, 1st Post, Need Help with SYP (Read 972 times)

mbolt512 · « **on:** May 18, 2018, 12:12:13 PM »

First let me say thanks. I've been checking in here for the last couple of years for some awesome information. While I still don't think I know enough to help anybody, I do unfortunately need some help. I make my living as a woodworker and I only saw and dry lumber for my on use.
Most of what I'm selling right now is made from SYP thus leading to this problem. Is there anything I can do to help control the sap problem? Here's what I did to arrive at these photos.
   1. Cut logs and let sit for a few weeks.
   2. Sawed 4/4 lumber and stacked with 1" stickers 16"oc and covered top of stack with tin.
   3. Air dried to 14%
   4. Moved stack to kiln, turned on fans and dehumidifier until 10%
   5. Pulled out dehumidifier and turned up heat to 180 F
   6. Reached 180 F then maintain for 24 hrs afterwards let cool
Note: I tried this same procedure at 160 F with similar results.

As you can imagine, this is creating a living H**L in the shop. Should I go hotter, cooler, longer, shorter or just give up? $:-\$ Any other fast drying local trees with awesome grain I could try?

mbolt512 · « **Reply #1 on:** May 18, 2018, 12:15:31 PM »

Sorry, This was supposed to be in Drying and Processing but I don't know how to move it.

Just Right · « **Reply #2 on:** May 18, 2018, 12:19:49 PM »

Does it clean up after planing? Is it tacky? I am just asking, I don't know myself. But like you, I know someone on here does. Good luck

mbolt512 · « **Reply #3 on:** May 18, 2018, 12:39:00 PM »

It's still somewhat tacky after it's been planed. (But Pretty)

firefighter ontheside · « **Reply #4 on:** May 19, 2018, 08:24:52 AM »

If you’ve set the pitch at 180°, it shouldn’t be a problem again unless the wood gets higher than 180.

mbolt512 · « **Reply #5 on:** May 19, 2018, 09:08:20 AM »

There was no surface sap until I set the pitch. It seems the heat brought it to the surface. If I heat it longer will it crystalize making it easier to cleanup? There were several places where it dripped off the edge of a board. In those places it turned dark brown and will actually crack and chip off when it's struck.

Southside logger · « **Reply #6 on:** May 19, 2018, 09:45:29 AM »

10% is a little low MC for SYP, that could be part of the issue.

GeneWengert-WoodDoc · « **Reply #7 on:** May 19, 2018, 11:18:59 PM »

When we "set the pitch" we are really evaporating the pitch or sap that would be liquid at room temperature. There is a lot of pitch left in the wood, but it will be hard at room temperature. It can soften when we heat the wood, such as with dull sandpaper...it clogs the paper quickly. While we are setting the pitch, there is a flow of the sap to the surfaces, but not all this pitch is evaporated. That is what you see now. Ok?

mbolt512 · « **Reply #8 on:** May 21, 2018, 02:25:01 PM »

Thank you Gene. I understand why it's moving to the surface, but is there anything else I can do to make it harder. The way it is right now, I can't even run it through the planer. It cakes up on the drive wheels and table surface to the point it won't feed after the first board. I was hoping that if I set the pitch longer it would crystalize and become harder. Also what happens to the pitch evaporation in an airtight kiln? I built my kiln from an old ice cream truck body so it's very tight and very insulated. When I turn the heat off after setting the pitch it takes at least 24hr to drop below 130 degrees. I'm actually having a worst time with the pitch now than I did when I only air dried my lumber.

Any help would be greatly appreciated.

ellmoe · « **Reply #9 on:** May 21, 2018, 06:15:43 PM »

In my experience the lumber, not the kiln, needs to be at temp. for at least 24 hrs.. We process some very pitchy pine. When I first started drying with the kiln at 160 for 24 hrs. I could run maybe a half dozen boards then would have to clean all the feed rollers. I changed two things, ran kiln at temp. for two days and pre-sprayed all the feed rollers so the pitch wouldn't stick. Big difference.

mbolt512 · « **Reply #10 on:** May 21, 2018, 06:59:27 PM »

What do spray the rollers with?

GeneWengert-WoodDoc · « **Reply #11 on:** May 21, 2018, 10:52:46 PM »

A planner generates heat and softens the remaining sap. Then when the knife cools, the pitch hardens.

With a tight kiln, the evaporated pitch will coat the walls. Probably six loads or more before you begin to see the coating.

You will have better machining results if you heat the kiln to 180 F instead of 160 F. A longer treatment time will also help.

You see more trouble now because the pitch ic concentrated at the surfaces, compared to air drying.

Forestry Forum
Sponsored by: