Flat Bottoms on Platters

[Tim Passmore]

Advice needed for getting a flat (even/smooth) bottoms when turning platters. Thanks in advance for your insight and expertise.

[Michael Mills]

I don't know if it will help but I have some soft aluminum bar of various lengths.
A light touch across the surface will leave light marks showing high/low places.
Helps me to see variations normally only seen after applying the finish.

[Brian Brown]

I'm not really sure why you want a flat bottom. If you are able to get a perfectly flat bottom, there is always a possibility that over time, the wood will absorb humidity, dry more completely, or just plain change shape because it wants to. This will make the turning wobble, or rock. I like to put a foot, or a bead ring on the bottom, so that most of the bottom is recessed up above the ring. Movement in the wood could still cause a change in the ring, but there is a better chance the turning won't be so wobbly. The recessed area also gives you a palette to add some decorative details, and a place to sign your piece. These details make the piece uniquely yours, and prove your attention to detail even on areas that don't usually show.

[Tim Passmore]

Brian---- I evidentially wasn't clear with my post. I was referring to the inside bottom not the exterior bottom (foot) area.

Michael----- Thanks for the tip.

[Barry McFadden]

I turn mine with my bowl gouge to the point I would be finished material removal then lightly go over the bottom with a scraper.

[brian zawatsky]

I use a bowl gouge & as light a cut as I can to get it flat, feel the bottom with the platter spinning for ridges/waves and mark them with a pencil. Then I use a negative rake scraper to remove the ridges and tool marks. You have to sharpen the NRS constantly because the burr wears away quickly, but it does a great job on platter and bowl bottoms.

[Thomas Canfield]

A ROS (random orbital sander) does wonders to help level a flat inside bottom of platter if the dust bag will allow. I use a bowl gouge prior to sanding.

[Brian Brown]

What??? You don't leave a Bead/foot on the inside too?!?! Sorry, didn't think that one out very well.

[Justin Stephen]

I turn mine with my bowl gouge to the point I would be finished material removal then lightly go over the bottom with a scraper.

Pretty much the same with me except I usually use a negative rake scraper. Doing a light pass with a sanding disc to highlight visually what you should already be feeling with your fingers is also sometimes helpful.

The random orbit sander idea sounds good. I may have to try that someday.

[John K Jordan]

Advice needed for getting a flat (even/smooth) bottoms when turning platters. Thanks in advance for your insight and expertise.

(Tim, I first thought you wanted the foot flat too! Say what?? )

I'm an oddball here because I use an unconventional method. Of course I've been asked before how in the heck did I get the inside bottom that perfect. No braggin', ust sayin'.

Note that I consider "flat" can be somewhat different than "even/smooth". If I get sloppy with my tool control and have a depression in the center I make additional "whisper" cuts down the side and across the entire bottom, or just in the center for a hump. For unevenness such as even very slight ripples (and any small "nib" in the exact center) I use a different method.

After my finish cuts I touch up with handled scrapers as needed - these days I like the Thompsons ground with a negative rake; round nose or the Sorby teardrop for tighter curves and closed-in rims on bowls. I then use hand scrapers to remove any remaining small ripples/unevenness. Anything I judge bigger than "small", back to the gouge or conventional scrapers.

scrapers_.jpg

The larger scrapers with very slight curves on the side are the best for platters. I use these sometimes with the lathe turning at a slow speed but often with the lathe off, especially near the center. I almost always scrape with the grain as you would with flatwork. This usually takes only a few minutes.

I can't fix what I can't see or feel. Once I completed and finished a small squarish platter and was horrified by very shallow concentric ripples on the bottom that were revealed when I took it off the lathe and tilted it in my hand. Now I do several things. First, run my fingers over the surface. You can feel ripples and unevenness that you can never see on a non-shiny surface. Second, for most woods I use a cloth to apply a bit of naptha to wet the surface and use a glancing light to inspect the bottom. This will usually show up the shallowest ripples.

Note that if the final finish is not glossy, shallow ripples may be hidden to the eye but you can still feel them. If the final finish is glossy the light will easily reveal any ripples.

One thing I almost always do which makes the scraping easier, more effective, and more relaxing (and gives my feet a break) - I unscrew the chuck from the lathe and sit in a comfortable chair in good light and smooth the bottom as needed. In addition, I often sand this way by hand, while seated, again with the grain. This will eliminate the horrible fine concentric scratches you see in so much face work. BTW, with some woods and situations I often sand with the figure as well as the grain where the figure is different.

One huge advantage of smoothing with a scraper is coarse sandpaper is almost never needed. Power sanding is rarely needed. Ask any fine furniture maker - a scraper can give an incredibly smooth surface. I usually don't need anything coarser than 320 grit. (Omitting the power sanding also eliminates clouds of dust.) BTW, when I do power sand I far prefer the tiny Grex pneumatic sander - it is a random orbital sander with good low speed control for very gentle sanding. I've taken my close-quarters/angled drill out of my turning area.

I find this method very effective. I should do some photos some day showing the before, the process, and the after of ripple removal.

Here are older pics of some things I would hate to do without the scrapers. The hand scrapers are especially useful on the squarish dished platters such as in the second photo. The hand scrapers are especially useful on the interrupted cuts on the wings. The one turned upside down to show the bottom shape (cherry) is the one I almost threw away after it was completely finished. I was able to repair the inside by hand (off the lathe) just in time for a wedding gift.

platter_PC012780_e_comp_small.jpg penta_plates_comp_small.jpg

Note that hand scrapers must be good quality and properly sharpened.

Sorry for the long response to your 20 word query. I always get carried away. Part of the problem might be typing on a real keyboard instead of an iPad.

JKJ

[Wes Ramsey]

I use a flat scraper both inside and out. Inside I use it to flatten the bottom. Outside I use it to do final shaping. Funny how a flat scraper can coax the perfect curve.

[Tim Passmore]

Barry, Brian, Thomas, Justin, John, and Wes----Thanks guys for taking the time to provide insight. I have a feeling, that no matter the technique, practice and patience are the keys to success-----like most things in life. I love the practice part��.

[John K Jordan]

I love the practice part.

If you don't do so now, you might try what I and some others I know often do when turning: Make each cut a practice cut.

After roughing a cylinder for a spindle, box, etc, rather than just quickly hog down to the target diameter/taper I like to make practice cuts with the skew for the smoothest possible cylinder. Try different techniques and different tools. Cut some beads and coves and grooves, cut them away. Try different stances and tool presentations and see what works with that particular chunk of wood. For example, doing this on a thin spindle in osage orange I discovered early at least THAT piece of wood was real "chippy" with a certain low-angle skew so I had plenty of time to experiment with different grinds and presentations before it got too thing.

When getting closer to the target shape, I start making each cut a finish cut, long curves and tapers as smooth as possible, sneaking up on the shape. By the time I do six finish cuts in a row the last one is a keeper!

Same thing for face work. When truing the top face of a bowl I might try to get it as flat as possible with various gouge grinds. Halfway through shaping the side I try different things and learn what is best for that chunk. Sometimes I play with shapes and stumble into something I like better than what I intended!

It is actually a quite relaxing way to turn!

The disadvantage of this method is it takes longer, may not be for the production wannabe or the type-A goal oriented. The advantages are obvious.

JKJ

[jared herbert]

So a question about the plates in the second picture. What are the approximate dimensions? Did you turn a round plate and then cut the sides off with a bandsaw to make the rectangular shape? Just wondering. I like the looks of them. thanks

[John Beaver]

A nice little trick is to take a stick of hot melt glue and lay it on the piece. It does a great job of showing bumps and divots. Then use a light scraper to fix those areas.