Older birch bowls – how to refinish (?s from a total newbie)
Problem: I just bought a used, older set of 5 matching/nesting birch bowls (15″ down to 7″), which I was excited to use for salads and the like, until I got home and realized that they have some “issues” — primarily, that they have what seems to be rancid oil build-up, and secondarily, that 4 of the 5 were originally lacquered on the outside, and that lacquer is starting to crack/fail in places. The bowls are nice (Alaskan birch), and have been relatively well cared-for otherwise — so I’d like to try to “revive” them rather than replace them (my husband of course thinks I’m crazy). I’m wondering how much I’m in for, and if I, a total newbie, will be able to do so well enough to make it worth it.
Regarding the oil residue: bowls are currently tacky, and have a strong “old oil” smell (that I didn’t notice or know to check for, when purchasing – had a cold!). I emailed the manufacturer (Great Alaskan Bowl Company) asking how to ‘degunk’ them and they suggested first trying a good dish detergent (Dawn) and a scrubber w/ very hot water, and repeating until gone, drying and using paper towls or rags to wipe off old oil that had surfaced. I tried a few rounds of that on the one bowl, and the tackiness has reduced, but it’s still there, and there’s still a strong ‘rancid’ smell, and I can still rub some yellow onto a paper towel if I push hard enough. I’d also read elsewhere you could try lemon juice and kosher salt (or pumice dust), so I tried that (w/ salt), and no big difference from what I’d achieved w/ the dish soap. The company rep had said to sand after I’d gotten the old oil off, progressing coarse to fine, but I don’t know if/when I’ll get to the point when I can really call them ‘clean’, before sanding.
Here’s what I’d like feedback on: Any tips/suggestions for how to better/more quickly remove the old oil? With the amount of time I’ve spent on this one bowl (and w/ less than satisfactory results so far), I’m doubtful that this approach will get me through all 5 bowls. Can I try to sand sooner, before the bowls are totally ‘degunked’? I only have minimal experience sanding, so have to ask – if I sand w/ the ‘bad’ oil still there, will it get sanded off (ideally), or, will that ‘bad’ oil get pushed further down into the wood in the process? Will the sandpaper just gunk up quickly too, w/ the oil residue?
Regarding the lacquer — I tried to get an angle in second photo that shows it — it’s as if the lines of the wood grain now have raised bumps/ridges on the outside, apparently from the lacquer starting to rise/fail. On smooth portions of the wood, it’s in good shape still — lacquer is also smooth. Is this really just a cosmetic issue, or do I have to worry about it affecting the integrity/life of the bowl, to not have the outside surface fully intact (although, to clarify, I don’t see areas where the lacquer/sheen is off, just perhaps starting to crack along grain lines)? The company rep told me I could just sand that off (‘might as well’, as long as I’d be sanding the insides), again, moving coarse to fine. Since I’ve got my work cut out for me on the insides, I’m thinking I’d just leave the outsides for now, unless I knew it was a matter of compromising protection of the bowl, by having a slightly-cracking outer lacquer. (BTW, they no longer lacquer those bowls – they realized it wasn’t lasting as well as hoped – these bowls are probably 20+ years old).
Re: tools (or lack thereof) — do I have to do all this by hand? No lathe, and we only own a small hand-held (orbital/pad?) sander, which I’m guessing won’t do me any good here. We do have a drill — could I attach pads (??) to that? But would that work w/out a bowl turner? I might be able to borrow/buy items, if there’s a great tool that would speed this process up for me — in sum, what should I be using to sand the curved bowls, inside and potentially out? What grit papers would you recommend, first for the ‘degunking’ of the oiled (but smooth) insides, potentially for removing the lacquered outsides, and in what progression/steps up to which finest grit for final refinishing? Or, perhaps the better question – should a totaly newbie even be trying to re-sand these bowls, or will I likely mess them up in the process? (I’ve read, that sanding itself is quite the art — does that apply to RE-sanding as well?) Is it ever possible to hire someone to do the sanding for me — where would I look?
Last question – may/may not be related – but I now notice a lighter streak that runs down the middle (one way) of most of the bowls — as if bleached just down the midline, in an area about 1″ wide (you can see this somewhat in the first photo I attached – runs from 9 to 3 o’clock). It’s consistent across the bowls. Any ideas as to what this is from, and if refinishing will lessen this effect?
Again, sorry for the newbie questions, and for so many of them, but I wanted some more experienced folks’ input and suggestions, before I commit to digging into this project. Thanks so much (in advance) for whatever help you can offer!!
Katie
Anchorage, AK
Replies
Some random thoughts 'till someone who knows what he is talking about chimes in.
It sounds like someone might have coated the insides with vegetable oil before packing them away. Mineral oil would have been better.
Some bowls tend to get out of round as they age so putting them on a lathe with a jam chuck can be tricky. If the walls are thick enough they could be re-turned and/or resanded. Picture #1 looks like it is still round.
There are thick and soft pads, and pads that flex a lot that turners used to use on bowl insides in conjunction with the spinning bowl. They were used on hand drills and the combination of spinning bowl and spinning drill made the sanding in essence random in nature.
I am surprised that lemon juice didn't help as I use it on cutting boards to bleach and sweeten all the time. On a flat cutting board a woodworkers scraper works. There are curved scrapers that might work but that involves buying tools and learning how to shape the hook edges and probably not the way you want to go.
The lighter streak that runs down through most of the bowls might be a natural grain or sapwood/heartwood coloration and might indicate that all the nesting bowls were cut out of the same blank of wood. Instead of a blank being hollowed out by turning the inside into chips, the inside of the largest bowl is cut out with a special tool which makes a smaller blank for the next smaller bowl and that in turn is cut out for the next bowl in the nest.
I'm quite sure that sanding will not "push the bad oil further down into the wood". As for sanding being an art, it is mostly hard work and the rules are basically: sand with the grain, not across, progress from lower grits to higher grits, 60, then 100, then 150, then 220 so that each grit removes the scratch pattern from the last one and leaves smaller scratches to be removed by the even smaller scratches of the next grit.
My inclination would be to try some 60 grit sandpaper and don't worry about gunking up the sandpaper. There are ways to de-gunk sandpaper but just use a new piece till the bowl gets clean, then progress up the grits. I would cut a large sheet of paper into 1/4ths, flex the back over the edge of a table by holding the sandpaper by opposite edges and drawing it across the edge first with 1 pair of edges and then the other. This allows the sandpaper to flex on the curve of the bowl without cracking the sandpaper. WARNING: do not use the edge of a good table and do not do this with the grit side facing down.
Warning Number Two: Wait and see if others have better ideas. These are just random thoughts from an amateur woodworker. There are a lot of folks on this forum with vastly better knowledge of this subject than me. Good luck.
Thanks
Swenson, thanks for the feedback/ideas -- every bit helps! Yes, that's what I suspect too -- original/previous owners used veg. oil or similar for conditioning --bummer. To be fair to the lemon juice method, I only gave it one go (and probably wasn't as vigorous, as I'd already done a bunch of dish soap runs just before). Good to know it works for you -- I'll try that again, and let it sit a bit more before scrubbing. These bowls are indeed round (at least to the naked eye) -- and yes, quite thick, ~1/2". Your idea on the light streak sounds like it might be right on -- at least the smaller 4 of the 5 bowls were a 'family tree' set -- from the same tree. Question about your idea of flexing the sandpaper over a table edge -- do you mean to do so as a 'pre-sanding' step, to make the paper(backing) more flexible? Makes sense to me, especially for the rougher/thicker paper -- thanks again!
To refinish these bowl put down the sandpaper, or rather save it for a final step. Remove the old finish with a chemical stripper. That will remove the old oil and lacquer and leave the surface better to accept a new finish. I would do inside and out simultaneously to prevent stress from possible moisture disparities. (This means serious stripping gloves.) It will also retain some of the patina of the wood as it has developed over the years. Methylene Chloride strippers are quickest.acting. You would want to fully neutrlize the stripper following label directions..
And, yes according to the manufacturer's web pages, the sets are manufactured from a single block that does mix sap and heartwoods. (The set of 5 sells for $650.)
Steve,
Thanks for the ideas. I'm hesitant however to use heavy duty chemicals on the food surface -- I'm afraid of what might leach into the wood and later come in contact with foods. Perhaps for the outside that might do the trick... any other suggestions for the inside, that would be more food-contact-friendly -- perhaps any 'natural' strippers (if there is such a thing, beyond lemon, etc.)?
Yes, it's a pretty set. Got it for $120, which I thought was a steal, but now I'm realizing I'm going to have to really work for that deal! :) I think it's actually a 4-family-bowl set (the smaller 4), as they are absolutley matching in grain, and all have the lacquered outside, which the company rep. said they did back in the 90s (before they realized it wasn't holding up well) -- they used it in part to 'mark' which of their bowls were in the family tree sets. The 15" bowl doesn't have a lacquer, which might mean it was added at a later date -- although whomever bought/sold it seems to have done a pretty good job of matching grains and markings. An 'in-law' bowl, I guess. Anyway, that's all I know! Thanks again for weighing in.
Katie
You never know.
" I thought was a steal, but now I'm realizing I'm going to have to really work for that deal! :) "
You never know, you just might have fun, and the satisfaction of reclaiming some beautiful wood and useful bowls. Even though sanding and finishing is not the most enjoyable part of woodworking for some of us, it might lead you to a new hobby.
Okay, now a woman collector will weigh in. I NEVER disagree with STeve (or hardly ever) but do NOT strip the interior of these--which you already rejected. And don't sand--at least not yet.
I thnk you haven't addressed this with enough elbow grease yet. And chances are these were just used for a long time for salads and this is what happened--or someone DID coat them with veg oil as a "preservative".
Get the plastic "scrubbies" and do the soap thing again. REally scrub it hard. Use full strength dish soap on it and scrub scrub. Rinse rinse rinse. Repeat. Then put some kosher salt in them with some lemon juice and scrub some more. Be sure, of course, not to soak these in water. And do dry them as well as you can.
Maybe report back. While the surface is wet with the above treatments, you could also scrape the gunk off with some sort of plastic pad that would conform somewhat to the shape of the surface. I guarantee that you will eventually be able to get rid of this stuff. Been there done that.
For the outside, depends on how bad it looks, but you may be able to get it off with a fairly benign stripper--you might even try wiping it with lacquer thinner to see if it will come off. If it isn't "too" bad, you could sort of just lightly sand and see if you can live with what it looks like.
What are you envisioning for use after you get them clean? That will determinine "next steps" somewhat.
It's true that methylene chloride is nasty stuff. But it is a solvent, and evaporates readily. It's dangers are from breathing the vapors or from skin contact with the liquid. Really good ventilation, not just an open window, is essential while using it. You certainly would want to remove any wax and the old finish sludge from the surface with naphtha or alcohol. But, with that removed there won't be MC remaining in the wood because it evaporates so readily.
Now I can't say, this is absolutely safe. But hazards will be through a more complicated process than leaving MC in the wood. Frankly, I can't say whether reaction products of stripping in the sludge that remains from MC strippers, or other saver stripping processes are dangerous or not. I can't help but think that this sludge can't be removed with other solvents and by some mechanical removal like sanding.
Elbow grease - showing improvement...
Hi all,
Sorry for the lapse in communication the past few days - I haven't figured out how to get notified by email when there's a new post (anyone know?), and got side-tracked in the meantime. Thanks for the additional ideas/comments.
Gretchen, the encouragement on the current course was heartening -- and indeed, after a trip to the store for supplies (Dawn to replace my 'eco-friendly' alternatives at home, and a new SOS plastic-version ('non-scratch') scrubbie), I am seeing further improvement. Haven't done more than another round or two, but the combination of the stronger soap, letting it really soak in after scrubbing, then using near-boiling water as the final scrub/rinse step, does seem to be making a difference -- the wood is lightening, and getting noticeably less gunky. I imagine a few more rounds of that, then perhaps more lemon juice/kosher salt, might do wonders.
The 'old/bad' oil smell is still there, but lessening. My only worry is that the (rancid) oil has penetrated deep enough into the wood that these efforts will be in vain. Anyone have knowledge of the propensity of birch to soak up oils? The manufacturer does treat the bowls -- they are "dipped and coated with a unique blend of seed oil, carotene, vitamin E and lemon oil that penetrates, conditions and seals the wood" (at least that's what they do now - not sure if it was the same when these were made). Does it happen that wood is too penetrated w/ (now-rancid) oil, that it would be deemed 'beyond hope', if trying to fully be rid of the smell, etc. of the old oil?
As for what I hope to use these for -- definitely food. Salads, serving vessels, etc. The 13" bowl does have a crack at one point at the rim, ~ 1/4" high, that goes down to a 'mini-knot-looking' mark in the wood, which appears to be whre the crack originates from. It's high enough on the bowl that I hope it won't be too big a deal, but is unfortunate, as that is likely the bowl we'll want to use most, for tossing salads, etc. Any suggestions for dealing with such cracks? I'm going to attach a photo of this crack, to give you an idea. You can see that in this part of the bowl there is another area (to the lower right of the crack) that has a 'mini-knot-like' characteristic, that creates another 'break' in the smooth bowl surface.
And as for sanding -- if I can get the wood bare enough by my Dawn/scrubbie and lemon juice/kosher salt efforts, will I still want to sand? Will that give another, more effective way of getting any residual rancid oil off, before beginning to recondition?
One final thing -- re: the light streaking that I see down the midline of each bowl -- I still have to wonder if it's just the natural/normal shading -- something tells me it is not (or not that alone). It looks as if it's not necessarily following the grain pattern, and is unusually light in just that 'zigzagging' narrow line. Any other ideas on what could be the cause? Just curious. I'll try to capture that in another photo, and post that now as well.
Bowl cracks.
Back in the days when I was doing a lot of hollow form and bowl turning I had a chance to spend a week with David Ellsworth, a turner of some renown. He warned his students that using CA glue, super glue, in bowl cracks could do more harm than good. The glue gets very hard, and as the bowl expands and contracts due to temp and humidity changes, the glue can act as a wedge, splitting the bowl even more. Just thought I'd pass this along.
Along with the growth rings that run around a tree, there are pathways that go horizontally from the outside to the inside of some trees. In boards that have been cut in a certain way, you can see those pathways as shiny rays running thru the board. Perhaps what you are seeing as light streaking are rays.
Good suggestion, to be cautious about using glue as filler -- makes sense. Thankfully the crack is at the very top of the bowl, so at least that area won't be in regular contact w/ food stuff... but when washing, it will be introduced to some water. Any suggesitons on how to try to protect/seal that area from moisture? I supposed when reconditioned w/ new oil, that might offer some protection, but is there anything else to consider applying, even just to that area? (I'm thinking beeswax or something heavier - although I have no idea of if beeswax and wood are a good pairing??)
If the bowl is cracked I think you need to retire it to some other use. it will just continue. BTDT also. It is "done'.
drats.
was hoping we could get some life out of it still, as a salad bowl. time will tell, I'm sure you're right.
Good. Now I'll offer more ideas when you get it down a bit. After you get it washed as well as you think, how about doing it with vinegar--scrub scrub. Then if still rancid smelling, try baking soda--you might sprinkle in on the wet bowl and leave it over night. And as a final thing I would bleach the bowl--Using your scrubby and maybe a bleach solution of several tablespoons of bleach to a quart of water.
The other thing was--are you going to use these for salad? Or just for "'show" and putting fruit, etc. in them. Good luck. I would put off talking about sanding until you see if these other things work. Don't overdo that hot hot water.
I am seriously suggessting to you that this is "cooking" problem, not totally a "woodworking" problem LOL
safe solvent
How about using EverClear (high-strength grain alcohol) as a solvent, along with the plastic scrubbie?
Haveno idea how lacquer thinner compares with mc stripper on food surfaces, and don't know that it would have any success. When I have had boiled linseed oil or tung oil based finishes remain sticky after several days, I have rather successfully removed them using lacquer thinner and a nylon scrubbing pad, like 3M scrubbies. IF you try this, use the scrubby with the grain as it is pretty aggressive. Have no clue whether it will have an effect on the sticky residue in the bowls or the finish outside, but may be an intermediate try between soap/lemon and methylene chloride. Lac thinner usually available in quarts at hardware stores and Home Depot/Lowes.
Thanks, might try that (some sort of stripping solvent) on the outside, if I decide the lacquer needs to go. For now, I'm trying to get the tackiness off the outsides too, as it seems there may be oil build-up there too -- not as bad as the inside, but it's there.
You might just try naphtha on the outside to remove stickiness. It works on wax so might do here.
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