Repairing cracks in a rustic apricot bowl [Archive]

CameronPotter

8th May 2006, 12:25 PM

Hi all,

I had rough turned and quick dried (using conc. detergent and metho mix) a piece of apricot from Sheddie.

It cracked a little across the pith (as expected, I know that it is a mistake to leave the pith in the centre). However, when drying out properly, the crack in the pith closed up and one opened up that went from the pith to the outside. It wasn't severe (and didn't actually penetrate through to the centre of the bowl), but it was big enough that it had to be dealt with.

I decided to use a accentuate the crack method, and I am sure that many of you have heard this before, but this is what I did:

1. Pour some thin superglue into the crack.

2. Pack the crack with used coffee grounds.

3. Pour on some more thin superglue.

4. Try to pack in some more used coffee grounds.

5. Put a gap filling coat over this.

6. Leave to dry.

7. Turn the rough into the final shape jsut as you normally would and the crack is a nice very dark brown/almost black highlight.

I will post a piccie tonight - but I have to do it on the sly as I think it might be a Mum's day pressie... :D

jmk89

8th May 2006, 12:44 PM

Cam

Nice work. Sounds like a great technique - I haven't used coffee grounds before to fill out superglue, but have used baking powder. But dark brown is a better feature than white...

I am just worried about what your wood is saying to you now - it sounds like it might be a bit like SWMBO when she has been out for a night on the tiles with her girlfriends: "give me coffee....my head is splitting":D

Jeremy

CameronPotter

8th May 2006, 12:54 PM

LOL! :D

Actually, I can't remember when I came up with the coffee thing (I may have even stole the idea from elsewhere). However, it works a treat.

The other thing is that coffee grounds are being mass produced all over the place and all you need to do is get on friendly terms with a cafe somewhere and you will have a ready source for more coffee ground than you could want. It dries fast an easily and doesn't hurt the smell of your shed either! :D

Oh, I meant to say before, when packing in the grounds, use disposable rubber gloves. :cool:

I have thought about using white powders (such as ground white marble etc) but, I reckon that a dark crack looks nicer - especially in light woods.

Cam

TTIT

8th May 2006, 02:01 PM

Tried to think where I had heard of a use for the coffee grinds recently. :( :( :( Got it!!!:D An aussie scientist has been working on a water filter that undeveloped countries can make themselves using their own meagre resources. He mixes the coffee grinds with clay as they leave cavities that capture the nasty bits in the water after being dried in cow-poo fired ovens. Apparently there's a few latte salons in Ethiopia!!:confused:

CameronPotter

8th May 2006, 02:38 PM

I think that I might stick to using our local tap water. ;)

Seriously though, it is funny how people think that coffee grounds are common where fresh water may not be... :confused:

CameronPotter

8th May 2006, 07:43 PM

Here are the pics as promised. The dark crack is the coffee and glue.

The mark beside it is in the wood. One shot also shows the bottom of the bowl (suprisingly crack free)!

Cam

Caveman

8th May 2006, 08:09 PM

Hey Cam - nice work. Reckon I'll have to try that at some stage - leaves a nice contrast with the paler wood.
I'm assuming the coffee grounds were dry at the time of superglue application???

Farnk

8th May 2006, 09:09 PM

Excellent result and a great effect.
I've usually used a paste made up of araldite and dust from the piece from sanding. I fill the cracks with the paste then sand the whole thing down afterwards, the end result looks like a bit of dark grain.

ss_11000

8th May 2006, 11:27 PM

nice work cam, gonna have to try that trick one day.

Skew ChiDAMN!!

8th May 2006, 11:35 PM

I've a few glass jars put aside with shavings & sawdust from various exotic woods. Ebony, Amarillo, Osage Orange, etc. I'll make a paste (sort of... I try not to break the lumps down) with either epoxy or PVA depending on the use of the final product, and they make some very pretty coloured & textured fillers.

Shedhand

8th May 2006, 11:41 PM

Hey Cam. Looks great mate. I'm glad my poor old tree was good for something. Here comes a greenie. :D

CameronPotter

9th May 2006, 10:20 AM

Thanks Guys, I am pretty thrilled about the way it came out (and it was my first "rustic" piece).

Caveman - yep, the grounds were dry, otherwise the glue would have gone off before penetrating properly.

Farnk - I have thought about that, but I was afraid that it would look like a repair, whereas this way I don't feel like I am trying to hide anything, quite the reverse actually. However, if it does just look like a darker bit of grain that might be a good idea.

Stirlo - you really should give it a go. I actually like it so much that I am considering purposely cracking wood just so that I can "repair" it... I was really suprised when it worked as well as it did.

Skew - Nice idea on saving old shavings and sawdust, but for now I don't really have the variety of wood to work with (although that is steadily increasing). :D I have thought about using coloured epoxy as a filler, but I thought that this looked very natural (which was more appropriate for the rustic edging).

Sheddie - thanks mate (even if the greenie did go missing in the ether ;) ). I have resawn most of the boards again and I can bring them around this evening if you want. There were two that were already quite thin and I didn't want to cut them so thin that they warped excessively - meaning that when you jointed them they disappeared as a pile of shavings!!

Cam

Shedhand

9th May 2006, 11:40 AM

Sheddie - thanks mate (even if the greenie did go missing in the ether ;) ). I have resawn most of the boards again and I can bring them around this evening if you want. There were two that were already quite thin and I didn't want to cut them so thin that they warped excessively - meaning that when you jointed them they disappeared as a pile of shavings!!

Cam
Sent greenie again. Weird! Yep drop around anytime mate.
Cheers

CameronPotter

9th May 2006, 11:43 AM

Alright, see you this evening.

Cam

Shedhand

9th May 2006, 11:58 AM

Alright, see you this evening.

Cam Bring the bowl. SWMBO wants to have a look. Me too. ;)

Skew ChiDAMN!!

9th May 2006, 12:08 PM

I have thought about using coloured epoxy as a filler, but I thought that this looked very natural (which was more appropriate for the rustic edging).

Agreed! For smaller items, like most turnings, flaws and inclusions are usually features and as such are closely scrutinised... coloured epoxy just doesn't cut it. In larger pieces of furniture where inclusions are just part'n'parcel of the timbers used, like red-gum, and not features in and of themselves, well then 'tis another story. :)

As for collecting shavings, by far the majority of mine have been from turning pens! I wish I could justify buying large chunks of ebony, etc. but reality dictates otherwise. [sigh]

CameronPotter

9th May 2006, 12:11 PM

Bring the bowl. SWMBO wants to have a look. Me too. ;)

Okeedoke. I love a chance to show off :rolleyes: (although the inside isn't as smooth as I had hoped it would be). :o

Darned hard wood, especially in the end grain.

Cam

CameronPotter

9th May 2006, 12:17 PM

Cheers Skew, I haven't done much larger work - but I do plan to in the future! I will keep that thought pattern in mind.

Also, I have been considering cutting up some macrocarpa at my girlfriend's place and turning some funky bowls. i.e. dye the wood and fill the cracks with contrasting colours. I reckon it would either turn out absolutely terribly or absolutely brilliantly. The trick would be to hope for the former. :rolleyes:

As for saving shavings, that is a good point, but when pen turning, I am usually a bit slack about cleaning my lathe between pens. But I might be more careful in the future as that is a nice idea. I reckon huon pine filling a crack in a darker wood would look nice! :D

Cheers

Cam

ss_11000

9th May 2006, 02:24 PM

Stirlo - you really should give it a go. I actually like it so much that I am considering purposely cracking wood just so that I can "repair" it... I was really suprised when it worked as well as it did.

Cam

how do you deliberately crack wood? will this method work on pens ( seen it done in a book with crushed stone ) when you get little cracks on the blank, can you enlarge them and fill them up with something?

CameronPotter

9th May 2006, 02:39 PM

Yes, it will work for pen turning - it is exactly the same process as with stone. Basically, it can be used to fill any void in wood (provided that the void isn't too big).

As for intentionally cracking wood, I have been thinking about that... :confused:

A few options:

1. Get a bluntish chisel and split the wood slightly from the end grain, then wedge it open slightly and fill the gap.

2. Get wet wood and break every drying rule you can think of... Put it next to a fire and move it from inside to outside frequently. Basically, try to dry it out very fast and unevenly - CRACK! Of course, if you over do it, you might end up with a blank that is cracked in half.

3. Get a wet pen blank, rough turn the pen (don't assemble it). Leave it for a week in a warm room. It should have cracked...

I am sure that others can think of other ways to crack wood. We have all done it before I would guess, just not intentionally... :o

Cam

ss_11000

9th May 2006, 02:41 PM

cool, thanx for the idea cam

CameronPotter

9th May 2006, 02:47 PM

I hope that it works for you.

Cam

Skew ChiDAMN!!

9th May 2006, 03:06 PM

As for intentionally cracking wood, I have been thinking about that... :confused:

A few options:
[...]

4. Use green fruit-woods like cherry. The hard part is stopping it from cracking! :(

3. Get a wet pen blank, rough turn the pen (don't assemble it). Leave it for a week in a warm room. It should have cracked...

I really don't recommend this 'un, it puts stresses on the glue which can cause delamination of the pen at a later date. Don't drill/glue until after the wood has stabilised!

Besides, pen blanks are so small that unless it's a really unstable wood, (like a squirrelly burl, or cherry) all you'd normally end up with are hairline annoyances. It's the BIG pieces (in one dimension if not more) that give the gaping cracks worth filling with something more than glue.

The best method is to grab a green log, strip the bark, sit it next to a heater duct, fireplace or similar "warmer than normal" place and wait. In a week you'll see where the major cracks'll be, in ensuing weeks they'll open wider'n'wider'n...

CameronPotter

9th May 2006, 03:15 PM

Cheers Skew,

I wasn't sure about the pen blank idea. I thought that the crack only needs to be fairly small to be noticeable on a pen (and I also thought thinner wood would crack easier). I am happy to stand corrected. :cool:

As for fruitwoods, well I did say that this bowl was apricot. :rolleyes: :D

Caveman

9th May 2006, 03:19 PM

Hey Cam - I don't envy you having to purposefully try and crack wood. The climate we have here is pretty much hell for wood and it seems to do pretty well cracking with no help at all :mad: - especially the unstable ones like acacia's and eucalypts. (Day temps upto 30'c, humidity <20% / night temps +-12'c, humidity >80% - this is mostly year round except during the rainy season when humidities are obviously higher).

I recently 'freed' a bowl from an ancient olive fencepost that would have lent itself to your coffee method. Luckily I have plenty more old posts so I can get round to trying it out.
As it is I used superglue and some sawdust, but I reckon the darker coffee grounds would have looked better.

Keep on experimenting and let us know how it turns out:) .

CameronPotter

9th May 2006, 03:26 PM

Great bowl Caveman! Greenie sent.

Yeah, Tassie is pretty easy on wood, but I don't actually have to try very hard to get wood to check anyway!! Actually this bowl was treated to achieve fast drying (hopefully without cracking) and it cracked anyway.

However, now that it has cracked and been repaired, I just happened to like the result. :cool:

Funny how that happens sometimes.

Cam

Skew ChiDAMN!!

9th May 2006, 03:27 PM

There's no trick to cracking wood... the trick is getting usable bits out of it. :D

I imagine you'd have more spalted woods and problems with straight out rot than we would, though?

CameronPotter

9th May 2006, 03:34 PM

As the days are dry I assume that spalting/rot isn't actually a big factor (except maybe in the wet season)???? :confused:

Caveman

9th May 2006, 03:40 PM

Thanks Cam.

There's no trick to cracking wood... the trick is getting usable bits out of it. :D

I imagine you'd have more spalted woods and problems with straight out rot than we would, though?

Yup - if the timber hangs around a wee bit then it can spalt quite easily/quickly, but if kept out of the weather (covered) then it's not too bad - this bowl was from a piece that i felt was pretty 'young' but still showed signs of spalting.
The other problem is the insects that have an insatiable appetite for wood - termites and borers