Stubborn milling marks and staining on elm

[SandyAndy]

Got a smashing piece of elm - a vertical slice through two big burrs and the edge of the trunk. I've braced and treated the back and am trying to get the front smooth and clean. There's some dark stains and milling marks I can't shift even giving it some well with 60 grit on a ROS. The surface isn't very flat.

What's the best next step? Just keep going with a sander? Or should I give it a gentle plane first. I don't have a hand plane or belt sander - so it's ROS, detail sander or an electric plane on very low depth moved gently.

Also, at what stage should I treat the front? I was thinking once the main sanding is done but with a final fine sand after treating just to clear off any residue. Using clear preservative then going to Danish oil.

Any advice appreciated! Thanks

 

[marcros]

A preservative under oil doesn't sound right to me- the oil needs to be able to soak into the wood, so you can't seal it first.

What are you making from it- does it need protection from heat, water marks, wine stains, etc?

 

[Yojevol]

Have you got enough thickness remaining. If so, and it's flat enough, I would give it a blast with the belt sander and then finish off with the ROS. This will get rid of the milling marks. As for the 'staining' I think that is more than skin deep. You may have to live with it. Put some trial finish on it to see how it comes up.
Preservative? If you wish. Is it already wormy? Where is it going to live? If indoors and not infected the finish will act as a deterrent.
This bit of elm was in a bit of a state when I acquired it 20 years ago and it still resides in our living room masquerading as a coffee table:-

Brian

 

[MikeG.]

Welcome to the forum.

This board clearly needs planing first. Stock preparation doesn't start with sanding. Without a plane, a planer, or a belt sander, you don't have the kit to tackle stock preparation, so you'll never get this board properly ready. I suggest you find someone with some more kit who can help you.

I'm a bit worried about "braced across the back". What do you mean by that? And why do you think you need a preservative? Is this board going to be used outside?

 

[MikeG.]

........If indoors and not infected the finish will act as a deterrent.......

If it is dry and warm, then there is no chance of woodworm attack, and the finish is then irrelevant. Outdoors, then that's a whole different ball game.

 

[SandyAndy]

Firstly thanks for all the replies. Sounds like just ploughing on with the ROS isn't the way forward.

I don't have a hand plane but I do have electric plane with variable depth. This also has rotating blades so will leave milling marks of its own, but if I keep the depth very shallow and go slow, will that put the milking within reach of a ROS?

Also, if planing something like this (burr with no real grain direction), at what angle to the milling marks should I plane and sand?

As for the preservative, I'm just using a water-soaked one against insects and rot (lumberjack triple action). There are a few worm holes I'm afraid (only about 10 in total) so I think it needs something. The guy who sold it me (more farmer than woodworker) said water-based preservative before oil.

As for the darker stains, yes fear that could just be part of wood but I'll have a go.

As for bracing, the thin bit was badly weakened and in danger of snapping off so have put recessed steel strips screwed into reverse side. Planning to wall mount it so should not be visible.

Thanks again.

 

[SandyAndy]

This bit of elm was in a bit of a state when I acquired it 20 years ago and it still resides in our living room masquerading as a coffee table:-
View attachment 4
Brian

Yes that's exactly how I would like mine to look!

 

[MikeG.]

.......As for bracing, the thin bit was badly weakened and in danger of snapping off so have put recessed steel strips screwed into reverse side. Planning to wall mount it so should not be visible..........

Ah, I thought this might be what you meant. Well, that's doomed to failure. Elm moves quite a lot*, and restricting that movement with something fixed across the grain will lead to misery. It will cup, and may split. Frankly, if you've got a wormy piece of wood which is so weak it needs bracing just to hang it on the wall, and you can't flatten it, then I suggest you put it on the fire.

Attempting to flatten it with a hand held electric planer will make a far bigger mess than you already have. The only things which can remove electric planer marks are planes or a belt sander, and if you've got them you don't need to use the electric planer anyway.

*I have an elm (and sycamore) breakfast table, and it is still on the move some 25 years after I made it.

 

[SandyAndy]

Thanks guys, have ordered a (hand) smoothing plane and sharpener.

Hope it doesn't buckle too much with the bracing but it's well seasoned and doesn't have to be completely flat. Warped=character, right?

Thanks again.