[whatalesyou1]

I have a Dewalt DW734 planer. Up until now, I have been very happy with it. I hadn't used it in a while and when I fired it up it was leaving large parallel scratches in my wood. I figured the blades had been damaged. I replaced them and I am still having the same problem. It is hard to see in the phone but it leaves numerous, unevenly spaced scratches the entire length of the board.

Any ideas?

I have torn the machine apart and cleaned everything I can reach but it still leaves scratches.

 

[ryan50hrl]

Top side of the wood while it's feeding? Get a piece and feed it through tight against the side, measure where the scratches are and transfer that measurement to the planner....now you'll know where to search for the offending sharp object.

 

[Brian T.]

Are the feed tables really clean?
If you can, get the edge of each plane blade pointing upwards.
Inspect with a very bright light. If the blades are sharp you should see nothing.
If the blades have hit sand grains, etc, there will be a little bent over/crumpled bit of edge.
That flat spot will reflect a real "spark" of light.

 

[TimPa]

i'm guessing that your new blades are damaged also. dirt in the wood?

 

[whatalesyou1]

i'm guessing that your new blades are damaged also. dirt in the wood?

I am starting to think this is the problem. I fliipped my new blades and ran the wood through. It had a couple of scratches but now I am getting more scratches again.

 

[Burt]

I have the same problem with my DW734. Tried same procedures as you to no avail. Now thinking that rollers have shrunk some and allowing the cast aluminum casing around blades to come in contact with plank surface.
Not much clearance there.
Been meaning to take my dremel and grind down some of the casting burrs near the blade area. Guess a call to Dewalt wouldn't hurt either.

 

[BWSmith]

Just to be clear here......a scratch is an impression
or groove,is this what you're refering to?

Or is it a "land"....like you have a knick in the blade/s.

It looks like a land in your photo,thats why I'm asking.

 

[woodnthings]

that's what I see

A raised narrow band, rather than a scratch or groove in the wood. My problem is IF you reversed the blades and they show no nicks, they may indeed be scratches.
Your planer may have a clearance issue with some part, could be the rollers, above the table

 

[TimPa]

I am starting to think this is the problem. I fliipped my new blades and ran the wood through. It had a couple of scratches but now I am getting more scratches again.

you can also try shifting one blade to the left or right. if it is nicked blades, you can sometimes make the cut usable. I have heard of material being in some wood that does this. or is the blade temper not up to par?

 

[Dave Paine]

I have a DeWalt 735. Lots of folks complain how easily the knives can get dings.

I think your knives have dings. The "scratches" are likely proud of the surface, if so the knives are dinged.

I flipped my knives and within a short time, as in a handful of passes, I had some new dings. Less than before.

Infinity Tools sells HSS blades for the 734 and 735 which are harder and should last longer - no surprise they cost more initially, but if they last longer, it will be worth it.

I will be buying these for my next knife replacement.

http://www.infinitytools.com/DeWalt...49/?key=gppc&gclid=CKWC2bHi3LkCFcmf4AodAF4ANw

 

[Hammer1]

It's always a good idea to brush/vacuum off your lumber before putting it through any machine. Never lay the board down on the floor, on a dirty workbench or pickup bed. It will pick up dirt and grit and this will nick a blade quickly. With a light source overhead, look directly on the edge of anything that should be sharp, chisels, knives, plane blades, etc. Move it so you can see any light reflecting off the fine edge. Any reflection indicates a dull edge. You don't need to know anything more than that when it comes to knowing if an edge is sharp but it takes some practice to be able to see it

Nicks in the blades will leave a pronounced "scratch" that is proud of the surface. Debris stuck in the planer, on the rollers or on the pressure bar will leave an indentation below the surface.