saw

[marcros]

This may be a daft question, but...

what saw do i need to cut gently curving components along the grain. the timber os 1 1/2" top 2" thick, and the curve is from zero to plus 2 1/2" to zero over about 5 feet. A coping saw would take forever, is it a frame saw that should be used for the job?

I dont have a bandsaw at present, although a cheap second hand hobby one with a tuffsaw blade would probably be man enough for the job- it isnt particularly thick timber after all.

 

[AndyT]

Interesting question!

It's not much of a curve, and the way you describe it it sounds like a convex curve only, which is easier than a concave. The detail will depend on how much wood you can waste / whether you need several components nested alongside each other.

My suggestions:

Use an ordinary rip saw but cut tangentially to the curve, then plane back to meet it. The planing can be done with an ordinary flat plane provided it has a fairly tight mouth.

Use a frame saw with about a half-inch blade. Rutlands used to sell these; Dictum still do (at a price) or you could find an old one or make your own.

I think an unframed padsaw would be too small for long rips in thick timber. The near-mythical 'table saw' might have been the answer once. (This is a pattern of hand saw included in old lists but not illustrated. There has been a lot of speculation about its form and purpose, with one theory being that it was a boatbuilder's tool used for sawing long shallow curves.)

And (although this is the hand tool section) you could use a powered jig saw - which might well be the cheapest option from a standing start. ;-)

 

[marcros]

andy, actually, the jigsaw might be a good option because i can mark it up using 3 pins and a length of something, then move it to a suitable position and use the same items as a fence to run the jigsaw base against, just to the waste side of the line.

The component is ex 6 x 1 1/2" or so, and has a concave curve on the bottom and a convex curve on the top. It is the top to the headboard and footboard of a bedstead, http://www.finewoodworking.com/woodwork ... l-bed.aspx which is grooved to take a floating panel, rather than having the complexity of nested elements.

 

[Phil Pascoe]

If you've not a bandsaw, a jigsaw with a good blade will do it easily. Having just seen the last post - it's possibly easier not to use a fence, because it's easier to correct if the saw starts to wander.

 

[marcros]

If you've not a bandsaw, a jigsaw with a good blade will do it easily. Having just seen the last post - it's possibly easier not to use a fence, because it's easier to correct if the saw starts to wander.

good point.

 

[jimi43]

I would seriously consider getting one of those cheap three-wheeled bandsaws based on the Burgess Powerline and Black and Decker BD3 designs.

I have said it so many times now I don't need to repeat how good these things are when properly tuned and that thickness of wood would be a breeze for this gem.

You can pick them up for a few quid on Fleabay....nobody wants them because they don't realise the capabilities but I assure you...once you get one of these and tune it up with some decent guides and a Tuffsaw blade...you will use it every day.

Three inch thick oak.....

What more can I say!?

Jim

 

[davem62]

hi mark
your welcome to come over and cut it on my band saw if nothing else works out,
regards dave

 

[marcros]

thanks Dave. The only problem with that is organisation- getting everything ready at the same time to dio it, rather than a couple of cuts here, and a couple of cuts there. The offer is appreciated though.

 

[Sheffield Tony]

If you find a jigsaw that will cut through 1 1/2 inches of hardwood without wandering around, trying to follow the grain, and that produces a perpendicular cut, can you let me know the make ? I have 2, and neither are up to it. They can't cut vertically through 3/4, let alone 1 1/2.

I made some curved parts in 2" think oak with a coping saw and spokeshave. Much shorter than the curves on that bed, but I think I would be looking for another way if I did it again. Much sweat !

 

[marcros]

i might just try and get a cheap bandsaw. My idea was to save up for a big startrite/hammer/similar, but investing a few quid into an old benchtop model and blade isnt going to break the bank, and may well do as a stop gap. It sounds like a bandsaw is the correct power tool for the job, and a framesaw the most suitable hand tool. They are both likely to set me back a similar sum i guess.

 

[Phil Pascoe]

I've a 16yo. Bosch jigsaw, and I've not had a problem that a new blade didn't cure. The smallest bit of wear on one side of the blade will make the saw run off line - I keep these blades for rougher work, then ultimately firewood. Over the years I've cut probably 20 - 25 tons with it.

 

[AndyT]

I could just echo Jim's suggestion - this is at full capacity with an Axminster blade that needs replacing, but it still cut perpendicular:

But mostly I think that if you want to do this mostly with hand tools, the final surface will need to be planed, so it's really an excuse to buy a compass plane

However, you will still have the problem of ploughing a groove along the concave underside. Some people would use a powered router; others would be happy with a chisel and mallet.

Others would say it's time to buy one of these (not my tool or picture!)

http://www.handplane.com/Planemaker-Gallery/details.php?image_id=451

 

[marcros]

The groove is another issue. i think that will be a powered router job, probably on the woodrat, although it might be an idea to try and do this before cutting the curve. Thankfully it is on the shallower curve, 1 1/4" from zero at mid point, but that might just be enough to cause issues with a plough place on a concave surface. i am lacking the mental capacity to work out the slope of the curve right now!

Are there any affordable compass plane models, or are they all a bit collectable now? would a spoke shave suffice?

 

[Cheshirechappie]

How about a bow saw? (Also known in some circles as a 'turning saw'. Sorry about that....) Flinn-Garlick saws sell them, and also sell 12" replacement blades quite cheaply if you feel like making your own. I suspect that Ebay would be a source of far cheaper ones, too.

I know it would be slower than a powered saw, but a bow-saw is a useful tool to have about (helped me out several times) and takes up less storage space than a bandsaw if the shop is tight for room.

Edit to add - could you solve the groove problem by laminating the component from three thinner pieces?

 

[marcros]

i cant laminate, short of cutting the existing timber into 3 pieces and gluing back together, which brings much of the problem full circle!

 

[AndyT]

My less frivolous suggestions for the groove:

1 - plough it while still square, quite deeply. After you have cut the curve, deepen the centre part (which will have become too shallow) using a chisel, following the established line. (The bottom of a panel groove does not have to be pretty!)

2 - use the 1950s diy equivalent of the expensive and collectible coachmaker's plough - the TekTool - they do come up on ebay from time to time and generally don't sell for much, despite getting a few mentions from Charles Hawyard.

3 - use a powered router with a bearing-guided slot cutter (as sold for making slots for biscuits).

Compass planes aren't all expensive - mine was cheapish as it has a chip off the casting which makes it less pretty but not less usable - but the final visible surface won't be much once you've got the groove in, so a spokeshave would do the job, as would coarse sandpaper stuck to a bit of guttering or drainpipe.

 

[bugbear]

2 - use the 1950s diy equivalent of the expensive and collectible coachmaker's plough - the TekTool - they do come up on ebay from time to time and generally don't sell for much, despite getting a few mentions from Charles Hawyard.

And Salaman. I have one and it would be my tool of choice for a 1/16" groove.

http://toolemera.com/Manufacturers%20%2 ... l-too.html

Box is priced at 19/6 which is surprisingly expensive.

BugBear

 

[AndyT]

Thanks BB - and for sharing your Tectool instructions with the world.

I missed them first time round at 19/6 - I think I had to pay £3.00!!

 

[marcros]

i bet it still isnt a bad investment at that!

 

[Andy RV]

You could also use the router to create the curve using a bearing guided bit or guide bush against an mdf template, that would leave you with a good finish and square edge.
Then I'd make the groove with a bearing guided groover in the router as well.