Spiral blade question

[cskipper]

I have a little (read very little) shop time over the weekend, so I though I'd practice using spiral blades. I have 2/0 FD "new" spirals. I'm getting the hang of using them, but they leave extremely rough inside edges (vertical lines). It seems that it will take forever to sand in addition to being difficult to sand (due to fragile cuts). Is this normal? How do you sand all those inside cuts? Or should my expectation of smooth inside cuts unrealistic with spirals?

 

[CarvedTones]

It is normal. You get the smooth surface because while the points of the blade are cutting a path, the sides of the points are like tiny planes lying flat on the surface of the freshly cut wood smoothing as you go. They can only plane because they are all in the same plane as each other and the surfaces of the cut. With spirals, some of those tiny planes are now tiny knives being dragged across at lots of angles other than parallel.

 

[sawduster]

Spirals tend to leave a rougher inside edge as it is more of a rasp than a blade .
2/0 is pretty small and would tend to flex more. It is also easy to put that size in upside down DAMHIKT :BangHead: What kind and how thick is the wood ? What's your saw speed ? I use faster speeds when using spirals
The back will have tons of fuzzies but these are easily removed with a small blowtorch ......details later if ya need 'em . If these fuzzies are on the top the blade is in upside down
Hope this helps some .....feel free to PM me if you have more specific questions, I'd be glad to help :icon_thum

 

[Joe Scharle]

Thanks for the tip Sawduster about the torch. I had stopped using them for that reason.

 

[Pop]

Good info Duster. The thing with spirals is they're also not for the faint of heart. The #1 I use for some detail and very small lettering breaks very easily. Quick release blade holders don't like spiral blades either. I've even tried the spirals with the flattened ends and they still break. I've started turning the blade slot inthe table around so the slot faces to the back and very rarely cut side ways. It's not unusual to go through 5-6 #1's in one project. The fret crucifix I just did went through 2. I used them for the inside of the leaves vein detail and the very tight cuts inside the figure of Christ. You don't get too many fuzzies on oak.

The torch is something I learned from the scroller site duster and I frequent. I bought the Bernz-o-matic one from Home depot for about $10 and it even came with a spare gas bottle (very small) because it's refillable.

REMEMBER... DON'T use it on the front of the work. DON'T use it while there's still glue residue on the work from the pattern. DON'T use it until you're sure the chemical you use to remove the pattern has evaporated or is dried off. DO move it back and forth quickly and don't stop at any one point for very long...wood does burn!

They do work great for removing fuzzies though!!

 

[cskipper]

Fuzzies on the top means the blades upside down? Mine were on the bottom of the wood, but still showed through all open spaces.

Obviously I am used to flat blades. I am also used to having smooth cuts, especially inside cuts, but not used to sanding all of those inside and fragile cuts. I would have to look it up, but I was cutting on the lowest speed my Hegner runs which is pretty slow. I really hate the rough cuts.:BangHead:

 

[sawduster]

I know exactly what you mean now and feel your pain ! I almost stopped using spirals for the very same reason, until I learned the torch trick
I usually burn mine off as I'm working and complete a section ( especially fragile parts ) . Laying the piece down flat, i go ahead and sand the back with a medium grit ....this usually gets the bigger chunks out of the way . Then I put it flat against a piece of plywood that I use solely for this purpose, stand it up and move a torch steadily back and forth .......keep moving the torch ! The fuzzies just disappear :gar-La; . It almost looks like a little fireworks show :mrgreen:
The plywood keeps the flame from licking through to the front
Afterwards hit the back with sandpaper again and the rest of the " crispies " should come off :eusa_clap A little shot of air and it should all be clean. You may have to dress a few areas with a needle file , but for me they are usually at a minimum
The biggest thing to be mindful of ......beside the fact that you are about to put flame to something you have worked so hard on, is not to burn the front edges of the cuts ( the back edges will burn some ) . It is very easy to burn small parts that are only connected by a single bridge . By constantly moving the torch, even stopping altogether sometimes, these parts never get hot enough to char
Practice on some scrap ....you'll have it in no time flat :icon_thum

For me , on both my Dewalt and my Hawk, I have found faster saw speeds to work better for spirals .....your mileage may vary :mrgreen:

 

[rickc]

The speaker at last month's TWA meeting mentioned spiral blades - didn't care for them, for the very reasons you have encountered. Rough cuts and the extra work necessary to clean up after using them. Did not recommend them.

Have you tried using the sanding strips that attach like blades? I am guessing they would not work, as your cuts are probably pretty narrow with a number of turns. The strips being about 1/4 wide aren't real good for that.

 

[rickc]

The biggest thing to be mindful of ......beside the fact that you are about to put flame to something you have worked so hard on, is not to burn the front edges of the cuts ( the back edges will burn some ) . It is very easy to burn small parts that are only connected by a single bridge . By constantly moving the torch, even stopping altogether sometimes, these parts never get hot enough to char
Practice on some scrap ....you'll have it in no time flat

Wondering - would using a hot air gun work better due to the LACK of flame? I know it is capable of generating enough heat to burn wood. (We won't ask HOW I know that! :embaresse ) But it might give that little extra cushion and margin for error by not having an actual flame.

 

[CarvedTones]

The speaker at last month's TWA meeting mentioned spiral blades - didn't care for them, for the very reasons you have encountered. Rough cuts and the extra work necessary to clean up after using them. Did not recommend them.

Have you tried using the sanding strips that attach like blades? I am guessing they would not work, as your cuts are probably pretty narrow with a number of turns. The strips being about 1/4 wide aren't real good for that.

I did not like spirals either. Besides the aforementioned problems, there is also a more esoteric one - they threw me out of the groove. It's hard to explain, but from seeing the work others have posted, I am pretty sure they understand. When you really get into scrolling, you start developing this knack for feeding the wood into the blade from the right direction almost effortlessly. The smoky smell of burning from side pressure which haunts you when you first start out becomes a distant memory. Spirals get you out of that mode.

The only reason I would use them is for work that was too large to orient the way I needed for some cuts, like a long sign or whatever. That means that the sanding strips wouldn't orient the right way either.

 

[sawduster]

I did not like spirals either. Besides the aforementioned problems, there is also a more esoteric one - they threw me out of the groove. It's hard to explain, but from seeing the work others have posted, I am pretty sure they understand. When you really get into scrolling, you start developing this knack for feeding the wood into the blade from the right direction almost effortlessly. The smoky smell of burning from side pressure which haunts you when you first start out becomes a distant memory. Spirals get you out of that mode.

The only reason I would use them is for work that was too large to orient the way I needed for some cuts, like a long sign or whatever. That means that the sanding strips wouldn't orient the right way either.

I know what you mean , but there is a groove with spirals also:icon_thum. different mindset, different feeding etc. It takes a while to remember not to turn the wood :BangHead: . Spirals take some getting used to and some folks just plain ol' don't like them. Personally, I can cut a straighter line with a spiral than I can with a flat . They are not the blade to end all blades but for me thay are a nice addition to my arsenal
I am so used to doing the additional clean up that it doesn't feel like extra steps anymore and for me the benefit far outweighs the effort . That is just me though, once I crawl into my saw, the world just melts away ( that zen thing again )

 

[CarvedTones]

I know what you mean , but there is a groove with spirals also:icon_thum. different mindset, different feeding etc. It takes a while to remember not to turn the wood :BangHead: . Spirals take some getting used to and some folks just plain ol' don't like them. Personally, I can cut a straighter line with a spiral than I can with a flat . They are not the blade to end all blades but for me thay are a nice addition to my arsenal
I am so used to doing the additional clean up that it doesn't feel like extra steps anymore and for me the benefit far outweighs the effort . That is just me though, once I crawl into my saw, the world just melts away ( that zen thing again )

You hit the nail on the head (or head on the wall :mrgreen with the turning comment. I like to take emery paper and ease the back corners of a blade so I can pivot on them in tight turns without leaving a mark (if that's cheating, so be it). Guess what happens when I try to turn a spiral blade? :evil:

I need to quit following these threads. Y'all have me jonesing for a new saw. That Zen thing; oh yeah! I get it carving also, but the work is more "bursty" and you don't lock in like you do with the saw. But you can carve almost anywhere and carry a project and tools in a pocket. I am headed down to Y camp with the boys this weekend and taking a little scrap of maple to practice a Viking dragon in relief on before I attack the side of an instrument.