Coping with tearout.

[Cheshirechappie]

We frequently have discussions about minimising tearout by setting up Bailey-type smoothing planes to deal with it. Perfectly valid approach, of course, but there are other strategies.

Stock selection - for components like drawer sides and runners, choose milder, straight-grained stock if you can. Such components often have to be finished accurate to a dimension or fit; bringing a drawer side to a nice fit in it's apperture but then having to take more off to remove tearout would be irritating to put it mildly.

Hiding it away - on the undersides of table-tops and insides of cabinets, don't worry about it if it's out of sight. Maybe not an appropriate strategy for a really fine quality piece, but a pragmatic approach for reasonable quality 'normal service' pieces.

Scrapers - the humble card scraper or scraper plane were invented for just this sort of job. Use the plane to get things as good as you can, and take out the rest with a scraping session. You do need to be careful to avoid working on too concentrated an area and forming hollows, though.

Sandpaper - some people regard it as cheating, but if it works why eschew it? On flat surfaces, use a cork sanding block and 100 grit to remove the worst, then work through 220 grit and 320 grit for a surface suitable for finishing. If the tearout is really bad, it may need power sanding to avoid a long session of rubbing, and (as with scraping) care has to taken to avoid forming hollows.

Infill planes - for those lucky enough to possess one (or more!) this is where these planes excell. Just don't expect them to cope with heavy stock removal.

Any comments and additions?

 

[G S Haydon]

Sounds good to me CC, very sensible.

 

[tobytools]

LN 55 pitch bed, on a LN plane.
A back bevel on a standard bailey plane would help.
I find that a super sharp iron is good enough when tackling potential tear out on certain woods.

Finer cuts work better, WITH THE GRAIN.


TT

 

[Fromey]

How about speed of planing? Is it my imagination that if I plane extra slow through a tearout area, it is more controlable?

 

[Peter Sefton]

Timber selection is all important, for critical parts like drawer sides use straight grain quarter sawn for minimal movement. When setting out the drawer the sides should be orientated so that when the drawer is being fitted you should be able to plane the lap dovetails in from the front of the drawer and the grain direction should be the correct way around to ensure no breakout.
Peter

 

[David C]

Scraper planes. I much prefer these to the card scraper as there is less tendency to dig holes in the problem areas.

David

 

[Trafalgar]

We frequently have discussions about minimising tearout by setting up Bailey-type smoothing planes to deal with it. Perfectly valid approach, of course, but there are other strategies.

Stock selection - for components like drawer sides and runners, choose milder, straight-grained stock if you can. Such components often have to be finished accurate to a dimension or fit; bringing a drawer side to a nice fit in it's apperture but then having to take more off to remove tearout would be irritating to put it mildly.

Hiding it away - on the undersides of table-tops and insides of cabinets, don't worry about it if it's out of sight. Maybe not an appropriate strategy for a really fine quality piece, but a pragmatic approach for reasonable quality 'normal service' pieces.

Scrapers - the humble card scraper or scraper plane were invented for just this sort of job. Use the plane to get things as good as you can, and take out the rest with a scraping session. You do need to be careful to avoid working on too concentrated an area and forming hollows, though.

Sandpaper - some people regard it as cheating, but if it works why eschew it? On flat surfaces, use a cork sanding block and 100 grit to remove the worst, then work through 220 grit and 320 grit for a surface suitable for finishing. If the tearout is really bad, it may need power sanding to avoid a long session of rubbing, and (as with scraping) care has to taken to avoid forming hollows.

Infill planes - for those lucky enough to possess one (or more!) this is where these planes excell. Just don't expect them to cope with heavy stock removal.

Any comments and additions?

Happy to see sensible and professional stock selection at the top of your list. These days it seems like the answer one is most likely to get is to dial up a tool supplier and buy a new plane.

Otherwise, a cabinet scraper then sandpaper.

 

[MickCheese]

This is really interesting having had a bad experience with this recently.

Watching with real interest.

I also found that when I jointed the table top I managed to orientate the boards so the grain was in opposite directions. Had I chose the orientation better I could have avoided some of the problems. As the plane traversed between glued up boards they tended to tear out. Does that make sense?

Mick

 

[matthewwh]

Charles: I couldn't agree more.

There are situations where you put up with having to tame gnarly wood or work against the grain in order to achieve a spectacular surface, but the potential reward has to be worth the effort - Mick's table top (above) would be a perfect example.

Reading your timber and selecting a piece that wants to be a drawer side, leg or apron is a far more efficacious approach than trying to make things into components against their will.

 

[bugbear]

This is really interesting having had a bad experience with this recently.

Watching with real interest.

I also found that when I jointed the table top I managed to orientate the boards so the grain was in opposite directions. Had I chose the orientation better I could have avoided some of the problems. As the plane traversed between glued up boards they tended to tear out. Does that make sense?

Mick

Quite right - most "kind" timber has a preferred direction, so if you glue up two boards with opposite preferences, you're quite literlly making trouble for yourself.

Of course, if you make a bookmatched pair, this kind of trouble is unavoidable.

BugBear

 

[Corneel]

And a sharp sharp blade! You can't plane irksome wood with a blunt blade and avoid tearout.

BTW, I don't understand how the infill made your list? What properties does it need to have to avoid tearout?

 

[Paul Chapman]

Any comments and additions?

If you have a lot of material to remove, a toothed blade will work well in wood which is normally prone to tear out or which already has a lot of tear out.

Cheers :wink:

Paul

 

[Peter Sefton]

Commercially abrading would be the answer normally through a wide belt sander.
Peter

 

[Corneel]

In the roughing phase removing cup or wind, planing across the grain is a good technigue.

 

[Jacob]

And a sharp sharp blade! You can't plane irksome wood with a blunt blade and avoid tearout.

BTW, I don't understand how the infill made your list? What properties does it need to have to avoid tearout?

I guess it's because they are not useful for general purpose use so get set aside for special purposes where the weight is an advantage - difficult grain.

 

[tobytools]

And a sharp sharp blade! You can't plane irksome wood with a blunt blade and avoid tearout.

BTW, I don't understand how the infill made your list? What properties does it need to have to avoid tearout?

I guess it's because they are not useful for general purpose use so get set aside for special purposes where the weight is an advantage - difficult grain.

I believe the pitch is higher on certain infill planes. Reducing tear out

TT

 

[Corneel]

Hmmm, the pitch of most classic infills is about 47.5 degrees, not really a remarkable difference. The weight doesn't help against tearout, it might help to power the plane through hard wood, but that is something else.

I asked because my infill has a 49 degree bed, is very heavy, has a thick blade, very well bedded and a huge mouth. It doesn't prevent tearout any better then a Stanley plane. Even when I put shims behind the blade, closing the mouth to 0.5mm, that doesn't help at all.

Just the fact that a plane is an infill, doesn't make it imune for tearout. It needs a specific mechanism to do so. A very tight mouth (0.1 to 0.2 mm), or a very high bedding angle (55 to 60 degrees) or a capiron set very close to the edge (0.2mm).

 

[tobytools]

Hmmm, the pitch of most classic infills is about 47.5 degrees, not really a remarkable difference. The weight doesn't help against tearout, it might help to power the plane through hard wood, but that is something else.

I asked because my infill has a 49 degree bed, is very heavy, has a thick blade, very well bedded and a huge mouth. It doesn't prevent tearout any better then a Stanley plane. Even when I put shims behind the blade, closing the mouth to 0.5mm, that doesn't help at all.

Just the fact that a plane is an infill, doesn't make it imune for tearout. It needs a specific mechanism to do so. A very tight mouth (0.1 to 0.2 mm), or a very high bedding angle (55 to 60 degrees) or a capiron set very close to the edge (0.2mm).

I do agree that it dosent make it immune to tear out but, it has some designs/ tools to help it prevent tear out, that would make it better than a standard bailey plane.
As said by the op good stock selection is key. The plane is lower down on the list.

Don't quote me but arnt some norris infill planes pitched at 55? Same as holtey.

Your being at 47.5 is just a good, depending on the angle of your iron.

I made and infill for a plane and I'm not sure what the pitch is but I know off the bat it's 45 and it's fine with certain woods.
I'm sure there is a science behind this matter but what ever works best.
TT

 

[Corneel]

When you take very thin shavings, a well made, sturdy plane with solidly bedded iron and flat sole is helpfull. Taking very thin shavings is a good strategy too to avoid or repair tearout, but far from perfect. I've had plenty of bords remaining cantankerous even with very fluffy shavings. And very thin shavings are not so nice when you want to get some work done.

The three methods I mentioned above (tight mouth, high angle, close set chipbreaker) make a plane quite immune for tearout, even with rather strong smoother shavings, in all but the most horrible Aussie woods. The latter might need even higher angles or combinations of these three, but I'm really no expert with them.

Infills have a mystical aura, which is kind of fun of course.

 

[Cheshirechappie]

Thanks for the input, chaps!

A couple of very interesting suggestions. I like the toothed iron suggestion - one that won't break the bank - and I'm intrigued by Fromey's thought on planing speed. Scope for a bit of experimentation there, I think. I do see the point about commercial workshops using a different approach - when work must be done to a time and budget, large machinery is the pragmatic solution. I agree with the point about using a scraper plane in preference to a card on larger flat surfaces, though.

On infill planes - I don't own one and have never (yet!) used one, so I can't claim any expertise. I did read somewhere that infills perform no better than a well set up and dead sharp Bailey plane, but where they excel is when the irons start to dull. The Bailey has shot it's bolt at this point, but the infills maintain their performance. I've no idea why, though.

On stock selection - this is something I don't always find easy, for two reasons. Not being a commercial workshop, I can't build stocks of timber suitable for particular tasks (quater-sawn oak for drawer stock, for example) and thus often have to go with what I have, or can get without extreme cost. That sometimes involves a bit of compromise, and having to use a piece of timber that may not necessarily be ideal for a particular purpose. The second reason is that I find reading sawn stock accurately quite difficult. It's much easier to see what you've got by way of grain direction when it's planed up, I find. (Sometimes, even identifying the species of a sawn board can be tricky!) I sometimes prefer to surface a board before deciding how to cut out such things as legs, stiles, rails and panels. Sometimes it's fairly obvious (waney edged board with obvious branch stubs at one end will be wild-grained there, so probably panel stock or chair back legs) but I've been caught out by square-edged boards in the past. I suppose it's all just experience, though.