Dewalt 734 Planer leaves marks on the wood from the knife screws

[John Hilborn]

We have a Dewalt 734 in our shop.
After installing a new set of non OEM blades, the planer started to leave faint marks on the surface of the wood in the exact location of the 8 knife hold down screws.

We have reversed the knives and the same problem is still occurring.

We installed a set of new Dewalt OEM blades and the same problem still occurs

[Aaron Rosenthal]

I’m trying to figure out how this could happen. I will look at my planer’s blade/knife geometry later today, since I’ve replaced my oem setup with a shelix head.

[Lee Schierer]

I wold suggest removing all the screws, the blade holder and the blade and checking to insure there is no chips or debris under or on top of any of the parts or down in the screw holes. Then carefully reassemble everything one step at a time insuring that the pins are in the alignment holes on the knife and the blade holder is also in place correctly. Then check each of the screws as you put them back in the holes one at a time. Tighten each screw just about finger tight. Finally starting at the center hole and alternatly work out from the cent tight each screw with the T-wrench. Finally torque each screw in the same fashion. Do the same for all the knives.

I would also check the rollers for any embedded debris.

[Randy Heinemann]

I would agree that taking the blades back out and cleaning the holders and making sure there is no sawdust or chips underneath the blades is a good suggestion if you haven't already done that. Screw marks would indicate that the screws aren't seated completely. (My comments are based on the assumption that the 735 uses eseentially the same blade installation and hardware that the 735 uses. With the 735, there is literally no way this could happen unless the screws aren't completely seated in their respective locations.)

[Scott Winners]

I have a 734 with a recent blade change done. I found some kind of goop (maybe melted sap) down in several of the screw holes. I tried using isopropyl alcohol but switched to a bore cleaning solvent from my rifle cleaning supplies. Also a razor blade to scrape the same stuff off the bedding surfaces for the knives. Little can of compressed air, eye shield.

[Richard Coers]

https://sawmillcreek.org/showthread.php?236361-Strange-Problem-with-DeWalt-Planer-Streaks-in-the-wood

[Dan Hahr]

I had this happen with my 735. It was after sharpening the knives for about the 3rd or 4th time. They were no longer wide enough to take a deep enough cut and the screw heads were taller than the edge of the knives

I would measure the width of the knives and see if they are in spec.

Dan

[Charles Lent]

I have never had this problem with my 735, but I remember reading that others had experienced this problem with the 734 and 735 planers. You might do some website research about this here and on other woodworking websites to see what was done. Sorry, I don't have the time for helping further now. My 735 is still using the original blades, so haven't had this problem, yet.

Charley