Interface pads for DA sander

[Kenneth Batten]

Trying to find a better solution for interface pads that can withstand the heat generated when using a DA sander.

This is the one I use currently https://www.woodturnerscatalog.com/p...ion-Air-Sander
(I run mine at 60psi and usually in the lower half of the variable control knobs range, depending on how much the disc is rotating.)

I've tried the ones from Craft supplies and from Vince's wooden wonders. His sand paper discs are great, but I believe his interface pads are meant for inertia drive sanders.

Anyone got any experience with any others?

[John K Jordan]

Kenneth,

I've never used a DA sander but I do use small random orbital sanders.

I have an opinion that may not be popular. From what I've seen and experienced if the paper and/or pad get hot there is too much pressure, too high of power, or too much lathe speed. I learned that lesson the hard way about 15 years ago.

Depending on the piece I often hand sand only, but when I sand with power it is always with a random orbital sander. (I use two pneumatic sanders - a Grex with 2" disks and a palm sander with 3" disks.) I sand at very low air power with the lathe off, usually with the piece taken off the lathe. Always dry wood, very light touch. I rarely use paper coarser than 320, sometimes can start with 400. Nothing ever gets hot, paper or pads.

I've used Vince's paper, some from Ken Rizza, some mesh "paper', and some other I bought long ago from Woodcraft or somewhere. All seem to work equally well with gentle use.

BTW, I remove tool marks with the lathe running using negative rake scrapers, then smooth with hand scrapers before sanding. After that, very little sanding is needed. The last pictures are of a student using the palm sander sanding a platter mounted on a carving/finishing stand and what she made.

scrapers_neg_rake.jpg scrapers_CU_.jpg sanding_IMG_20171212_094330_319.jpg Kristina_platter_finished_comp3.jpg

Curious: Are you sanding large bowls or platters?
What kind of wood?
Are you sanding tearout?
What grits are you using?
Are some worse than others?
Are you sanding with the lathe running or turned off?
Are you using a very light pressure?

JKJ

Trying to find a better solution for interface pads that can withstand the heat generated when using a DA sander.
This is the one I use currently https://www.woodturnerscatalog.com/p...ion-Air-Sander
(I run mine at 60psi and usually in the lower half of the variable control knobs range, depending on how much the disc is rotating.)
I've tried the ones from Craft supplies and from Vince's wooden wonders. His sand paper discs are great, but I believe his interface pads are meant for inertia drive sanders.
Anyone got any experience with any others?

[Don McClure]

I do power sand all the time and use all paper and pads from Vince's. Initially I experienced pads coming apart until I realized it was due to heat generated by improper techniques such as too much pressure, sanding too fast, using worn out paper, etc.
Vince Sells quality supplies and with proper use the pads will last.
I use an electric angle drill from Harbor Freight.
Let the paper do the work!

[Kenneth Batten]

Kenneth,

I've never used a DA sander but I do use small random orbital sanders.

I have an opinion that may not be popular. From what I've seen and experienced if the paper and/or pad get hot there is too much pressure, too high of power, or too much lathe speed. I learned that lesson the hard way about 15 years ago.

Depending on the piece I often hand sand only, but when I sand with power it is always with a random orbital sander. (I use two pneumatic sanders - a Grex with 2" disks and a palm sander with 3" disks.) I sand at very low air power with the lathe off, usually with the piece taken off the lathe. Always dry wood, very light touch. I rarely use paper coarser than 320, sometimes can start with 400. Nothing ever gets hot, paper or pads.

I've used Vince's paper, some from Ken Rizza, some mesh "paper', and some other I bought long ago from Woodcraft or somewhere. All seem to work equally well with gentle use.

BTW, I remove tool marks with the lathe running using negative rake scrapers, then smooth with hand scrapers before sanding. After that, very little sanding is needed. The last pictures are of a student using the palm sander sanding a platter mounted on a carving/finishing stand and what she made.

scrapers_neg_rake.jpg scrapers_CU_.jpg sanding_IMG_20171212_094330_319.jpg Kristina_platter_finished_comp3.jpg

Curious: Are you sanding large bowls or platters?
What kind of wood?
Are you sanding tearout?
What grits are you using?
Are some worse than others?
Are you sanding with the lathe running or turned off?
Are you using a very light pressure?

JKJ

The sander I am using is a random orbital sander, I could be wrong calling it a DA sander.

Curious: Are you sanding large bowls or platters? - My main issue is on side grain turned bowls, normally the initial curve and sides.
What kind of wood? - My last struggle was with spalted silver maple, the black cherry isn't as bad.
Are you sanding tearout? - No
What grits are you using? - I use the lower grits for smoothing, 80-120 and then at least move up through 600, depending on wood species and if I can still see scratches.
Are some worse than others? - The lower grits are my trouble area, I don't have any issues after.
Are you sanding with the lathe running or turned off? - With the lathe off
Are you using a very light pressure? - Definitely with the higher grits. I only try to use enough pressure to hold the sand paper to the work.

You mention using negative rake scrapers and card scrapers to clean up before sanding.. I believe I need to become more familiar with them. I have one negative rake scraper and a set of card scrapers.

[Reed Gray]

Okay, I am clueless, what is a DA sander??? Heat, usually caused by using too high speeds, and/or too high speeds causes most interface pads to delaminate. I never sand over 600 rpm or so... I use the pads from Vince, and his blue abrasive.

robo hippy

[Kenneth Batten]

Okay, I am clueless, what is a DA sander?

robo hippy

Mine, technically isn’t one but that’s what they call it. DA stands for dual action, which means it’s a orbital and a random orbital. Some of these you can lock out of the random orbital movement giving it the dual action term. I just can’t lock mine out.

Here is one of the issues I’m running into, am I running my speed too fast?

9DFC218E-B433-4C30-B500-DFAA672F7F07.jpg

[John K Jordan]

You mention using negative rake scrapers and card scrapers to clean up before sanding.. I believe I need to become more familiar with them. I have one negative rake scraper and a set of card scrapers.

As you might see in the photo (repeated here), I grind the NRS a bit like a skew with equal angles on both sides (60 deg included angle).
scrapers_neg_rake.jpg burnisher_IMG_6767.jpg

By changing the side the burr is on I can use one as either a "right" or "left" hand scraper. The scrapers shown are from 3/4" and 1" Thompson steel, two from scraper stock and one from a spare skew chisel. I shape heavy scrapers on an 80 grit CBN wheel and sharpen on a 600 grit CBN. I generally use the burr right off the grinder until it wears away (fairly quickly) then burnish a more substantial burr with a carbide rod.

I've seen a number of "pro" turners with similar scrapers with edges ground way back on one side but every one I've seen is rounded over the tip. I sharpen with a bit of "almost' flat at the very tip. I find the flat perfect for putting a final touch on a flat or shallow curved surface after scraping away the gouge marks with the rounded side. Following the NRS with the hand scrapers have vastly improved my bowl and platter surfaces.

To make the hand scrapers I like to start with fairly thick high quality cabinet scrapers and shape curves on the edges. I pick one that most closely matches the curve I'm smoothing and always scrap "downhill." I use maybe 6 different curves in large scrapers and a bunch of smaller curves, plus some small mostly straight edges. Several companies sell small curved hand scrapers but all I've found are pretty thin. Making them myself from heaver steel makes a better scraper.

After some experimentation, I found the best way to shape the scrapers is with a belt/disk sander. I use a Rikon with a 1" belt and a 6" disk (I think). The sander does not heat the steel nearly as much as a CBN wheel. After shaping, I touch up the edges with a 1200 grit CBN wheel on a Tormek, use the scraper directly off the wheel, then when the burr wears away I add a new burr with a carbide burnishing rod. I also use a couple of 1/8" thick Stewart-McDonald scrapers, generally marketed to violin and guitar makers.

I almost always use the hand scrapers off the lathe with the chuck mounted on a carving/finishing post (from Best Wood Tools). I can see what I'm doing a LOT better this way than while bending down with the piece mounted on the lathe. Before I got the mounting post I just took the chuck off the lathe and held in between my knees while sitting in a chair. After scraping and initial sanding, I always wipe the surface with naptha and turn it in my hands under a good light. This makes any imperfections, such as sanding scratches or worse, concentric ripples or center depression/hump obvious, even if they are very minor. I hate it if defects like this don't show up until the finish is applied!

As mentioned, the NRS/hand scraper method lets me use far finer sandpaper than I used to, and give me better surfaces. Most of the time I can start with no coarser than 320 paper, although I'm no sandpaper snob - I'll use coarser if I need it. So far I've almost never needed coarser than 220.

I show this piece at demos as an example. It's eastern red cedar so it is soft and fairly easy to scape smooth and sand. Somehow I got it smooth enough before sanding where it didn't need paper coarser than 600 grit. I think I sanded it some with 600 grit in the ROS and the rest by hand. ("danish" oil finish)

penta_platter_cedar_IMG_7434.jpg

It sounds like you are simply using too much pressure or speed or both. I learned on one of my first bowls, another piece from ERC, about getting sandpaper too hot. I was following instructions from an experienced turner to hold a piece of scotchbrite between the sandpaper and fingers to keep the fingers from getting too hot while sanding with the lathe running. This was horrible advice! The fingers were fine but many heat checks formed inside the bowl. Ack. This was when I hit on making a curved hand scraper to smooth instead of coarse sandpaper. At first I scraped with the lathe running, much later I went to larger scrapers and mostly smoothed with the lathe off. (I thought I'd come up with something new but recently read a book from the '50s that described using hand scrapers to smooth wood turnings. Ha!)

This is the early cedar bowl, I think my 3rd or 4th real bowl when I started turning, guessing maybe 17 years ago.
cedar_bowl.jpg

If you are interested I'll try to take a photo tomorrow of the hand scraper shapes I eventually found the most useful, more useful than those in the old photo I included earlier.

JKJ

[Kenneth Batten]

If you are interested I'll try to take a photo tomorrow of the hand scraper shapes I eventually found the most useful, more useful than those in the old photo I included earlier.

JKJ

Definitely! Thanks for all the great information! I'm spending way too much time trying to make it through the lower grits, I feel like this approach would save

[Reed Gray]

I have almost no experience with the random orbit sanders. First attempts indicated that they were very slow for the coarse grits, but good for the polishing grits, which is why I use the angle drills. They also seem to have really high orbiting speeds. Same thing with the mesh type of abrasives. Other than that, getting the cleanest surface before you start to sand is probably the best time saver. I don't use the card scrapers. For most of what I turn, the shear scrape is the best clean up cut I have found. Other than that, if the wood is being really difficult, a 600 grit edge on the tool can be the only thing to get it clean enough to start sanding.

robo hippy

[John K Jordan]

If you are interested I'll try to take a photo tomorrow of the hand scraper shapes I eventually found the most useful, more useful than those in the old photo I included earlier.
JKJ

Definitely! Thanks for all the great information! I'm spending way too much time trying to make it through the lower grits, I feel like this approach would save

Ok, I finally got some pictures today. I'll try to work up something to post tonight. I might start a new thread so it will be easier to find in case someone else is interested too.

JKJ

[Kenneth Batten]

Ok, I finally got some pictures today. I'll try to work up something to post tonight. I might start a new thread so it will be easier to find in case someone else is interested too.

JKJ

Thanks a lot for your help. I managed to get out to the shop tonight and worked with scrapers some, I'm no expert but it did help my troubled areas. Also, I stopped using the ROS on the inside lip of the bowl and switched to my drill to be able to flow with the grain. That helped as well! Managed to move through grits much faster this way.

Ps - I did order a thicker set of scrapers as well. They came from here. https://www.stewmac.com/Luthier_Tool...e_Scraper.html

[John K Jordan]

Thanks a lot for your help. I managed to get out to the shop tonight and worked with scrapers some, I'm no expert but it did help my troubled areas. Also, I stopped using the ROS on the inside lip of the bowl and switched to my drill to be able to flow with the grain. That helped as well! Managed to move through grits much faster this way.

Ps - I did order a thicker set of scrapers as well. They came from here. https://www.stewmac.com/Luthier_Tool...e_Scraper.html

I have that Stewart MacDonald set - they are excellent. They are about 1/8" thick, completely rigid unlike the "normal" cabinet scrapers. They are sharpened differently too, used without burnishing a burr. StewMac has a video. I bought some 1/8" O1 tool steel to try making some of these with different shapes. Maybe this winter...

I didn't get a chance to write up something about the scrapers yet, didn't even get them downloaded from the camera. I had to drop everything else and do some sawmilling, chainsawing, wood processing, tractor work, and small engine repair. Supposed to rain tomorrow - maybe then.

JKJ