(Big) gap fillers!

[Chris Goodhand]

Over the years I have made a few pieces that have resulted in large holes (bark inclusions). If these holes are situated in awkward locations (e.g. at the bottom of bowls), they become useless, however, I have kept several of them as the wood itself is too attractive and I can't bring myself to destroy them!

Can anyone recommend any attractive and fairly easy to apply fillers? Colours or type of material is of no consequence to me as I would just like to experiment on saving these pieces. The holes in question, while more than mere splits, are not huge. Generally they are in the 1" to 2" square sizes.

I have seen many examples of filled work from magazines, so I know there must be solutions out there! I live in Canada so am prepared to have to order any product suggestions on-line (not too many turning retailers in this country).

Any advice would be much appreciated.

Many thanks.

Chris G.

 

[john lucas]

Inlace or colored epoxy are two good possibilities Inlace comes in a wide variety of colors and you can add colored powders and chips that they also sell to alter its appearance. It has the advantage of thickening and hardening fairly quickly so you can work with it that way.
Epoxy has lots of options since it can be thickened and colored to do what you want to do

 

[odie]

Chris.......

You see here some rather large gaps in a Cherry burl bowl. At the widest point, the gaps are close to 1/8th inch, and go all the way through. These are filled with Devcon clear epoxy. You'll need to position the bowl so that the top of the opening is facing straight up (to prevent oozing out). Put tape over the bottom of the crack and fill the crack to overflowing on top. After the crack is filled, put tape over the top of the crack. It's best to use a "breathable" cloth tape, similar to medical cloth tape used in some bandages......this is so the ambient air will penetrate and dry the epoxy. I'm using "hockey tape", which is used to wrap ice hockey sticks. It's cloth, and breathable. The great news is the hockey tape doesn't stick to the epoxy after it's hardened......it's easily peeled off, leaving nothing but the epoxy.

Once the gap is filled, and exposed epoxy is sealed with the tape on both sides, you can go on to fill the next gap......with the breathable cloth tape in place, it's no longer necessary to worry about the epoxy oozing out of the crack prior to hardening....(gravity is no longer a consideration.)

ko

 

[Richard Wilabee]

The clear epoxy doesn't seem to show up as clear in the pictures it looks darker like the crack. Looks great!

Chris.......

You see here some rather large gaps in a Cherry burl bowl. At the widest point, the gaps are close to 1/8th inch, and go all the way through. These are filled with Devcon clear epoxy. You'll need to position the bowl so that the top of the opening is facing straight up (to prevent oozing out). Put tape over the bottom of the crack and fill the crack to overflowing on top. After the crack is filled, put tape over the top of the crack. It's best to use a "breathable" cloth tape, similar to medical cloth tape used in some bandages......this is so the ambient air will penetrate and dry the epoxy. I'm using "hockey tape", which is used to wrap ice hockey sticks. It's cloth, and breathable. The great news is the hockey tape doesn't stick to the epoxy after it's hardened......it's easily peeled off, leaving nothing but the epoxy.

Once the gap is filled, and exposed epoxy is sealed with the tape on both sides, you can go on to fill the next gap......with the breathable cloth tape in place, it's no longer necessary to worry about the epoxy oozing out of the crack prior to hardening....(gravity is no longer a consideration.)

ko

 

[odie]

The clear epoxy doesn't seem to show up as clear in the pictures it looks darker like the crack. Looks great!

Richard.......If you catch the light just right, you can see clear through the epoxy from one side to the other. It does tend to take on a darker tint to it, and when cracks don't go all the way through, the epoxy doesn't look very clear at all. On darker woods, the clear epoxy repairs are even more successful, because they are less noticeable yet......

ko

 

[Joe Greiner]

Here's a gap filled with epoxy and key-cutting shavings: http://www.aawforum.org/photopost/showphoto.php?photo=5998&title=bald-cypress-vase&cat=500

Closeup here: http://www.aawforum.org/photopost/showphoto.php?photo=5999&title=close-up&cat=500

I fill the gap proud of the final surface, then turn and/or sand to the final profile.

I also like to use epoxy with coffee-grounds. The coffee grounds have light and dark components. After cutting and sanding, it looks like miniature terrazzo.

Joe

 

[Gary Chapman]

Here is a cohttp://www.aawforum.org/vbforum/asset.php?fid=7959&uid=18833&d=1422365780uple in-lace ,turquoise filled pieces. Gary

 

[John Torchick]

Don't two part epoxies cure by a chemical reaction rather than air drying? Just curious.

 

[Mark Mandell]

Don't two part epoxies cure by a chemical reaction rather than air drying? Just curious.

You are correct. There are no solvents in epoxy to evaporate nor is oxygen a necessary component of the curing chemical reaction between the resin and the catalyst. That said, when pouring/casting epoxy such that its cross section is more than 1/2" thick it's good practice to allow as much surface as possible to remain open to allow for reaction heat to dissipate. Too large a pour in an enclosed space can generate enough heat to deform and/or fracture the gelled resin.

Mixed epoxy can also be thickened with a variety of materials to prevent its "runny" character. Micro balloons and powders can be mixed in to create a paste. Screened wood flour works quite well as in the photo of a walnut surface

 

[Owen Lowe]

Screened wood flour works quite well as in the photo of a walnut surface

I frequently add to my collection of various wood dusts when I sand pieces. So far I have black walnut, sycamore, white oak, and cherry. These are my most used local woods and the ones I will most likely need a good match for. Adding some old dry coffee grounds to the dust and epoxy lends a very natural looking crack and knot filler.

 

[odie]

Don't two part epoxies cure by a chemical reaction rather than air drying? Just curious.

You are correct. There are no solvents in epoxy to evaporate nor is oxygen a necessary component of the curing chemical reaction between the resin and the catalyst. That said, when pouring/casting epoxy such that its cross section is more than 1/2" thick it's good practice to allow as much surface as possible to remain open to allow for reaction heat to dissipate. Too large a pour in an enclosed space can generate enough heat to deform and/or fracture the gelled resin.

Mixed epoxy can also be thickened with a variety of materials to prevent its "runny" character. Micro balloons and powders can be mixed in to create a paste. Screened wood flour works quite well as in the photo of a walnut surface

View attachment 8177

Good catch, gentlemen.....you can now consider me informed!

Before I arrived at the hockey tape, I tried several other kinds of tape that didn't work as well. I figured the "breathable" component had to do with the ambient air, and I now stand corrected. The fact that the hockey tape allows you to handle the epoxied bowl, without sticking, or gravity effecting it, makes it a good choice to do this kind of repair......whether or not my assumptions were correct.

ko

 

[john lucas]

One thing I've had problems with when using sawdust as a filler is it can look like you filled the gap with pressed wood. Not a good look in my opinion. I have used it successfully in a lot of places and it works well in smaller cracks and defects. It's the larger ones that tend to look odd when filled this way. At least that's my experience. Others may have better success. I prefer to mix up something that adds contrast and highlights the crack since it's rare that you can mix it up well enough to hide it. When I fill in knots I mix colors that are similar or darker than the knot and will often leave the mix transparent so it picks up the color of the surrounding wood and looks more natural.
I have bought Inlace products from this place. I didn't check the current prices but they used to be very reasonable and carried a larger variety than others. The chips and powders also mix well with epoxy.
https://www.turtlefeathers.net/

 

[Mike Brazeau]

If it is salvageable, I general saturate bark with thin CA and then maybe fill around it with something. I usually use 5 minute epoxy, West Systems have a kit of two four oz bottles that Exotic Woods in Burlington sell or Lee Valley also have a small kit from another manufacturer. For filler in cherry I use ground red shale and it comes close to the color of the pitch inclusions cherry has. LV have a series of earth pigments. Eugen Schlaak uses black embossing powders for contrast. If you have a laser printer, there is black toner left in the cartridge even though the printer says it is MT. I have never like the brass filings option or coloured sparkles. Bought some years ago and they are in the same drawer as tools that looked better at the show than in practical use. I keep sanding dust from individual woods. Used to use 35 mm film containers to store but afraid they are rare as hen's teeth now. Small baggies or envelopes also work. I do like Turquoise Mineral powder and got some from Craft Supplies USA years ago. They use US Postal Service, so no additional customs costs when importing low cost orders. Makes a nice contrast in light or dark woods. You can also buy finely divided metal powders, but I have never explored. In small cracks, I also use CA and any of the above as it is quicker.

 

[Bob Howell]

I have a lot of scrap veneers of dark woods; Indian rosewood, ebony, etc. Many up to 1/8 thick.

I rub water resistant pva glue on splinters and stuff into the splits/holes. I like dark woods for fillers over lighter options. Once the hole/split is sound/strong, I often use a small drimmel type tool to detail the area rather than fill it. Large sawdust fillings don't appeal to me.

I repaired several cracks on the rim at the pith with thin splinters of black veneer. I roughed out 4-5 12" bowls from spalted magnolia. Bad cracks appeared in half of them so I fixed them this way last year.

Indian rosewood works great with spalted pecan.

 

[Gretch Flo]

I have a lot of scrap veneers of dark woods; Indian rosewood, ebony, etc. Many up to 1/8 thick.

I rub water resistant pva glue on splinters and stuff into the splits/holes. I like dark woods for fillers over lighter options. Once the hole/split is sound/strong, I often use a small drimmel type tool to detail the area rather than fill it. Large sawdust fillings don't appeal to me.

I repaired several cracks on the rim at the pith with thin splinters of black veneer. I roughed out 4-5 12" bowls from spalted magnolia. Bad cracks appeared in half of them so I fixed them this way last year.

Indian rosewood works great with spalted pecan.

Bob-do you have a picture??? Can't see how "splinters" can make a "solid" appearing fill. Gretch

 

[Bob Howell]

I hope this clearly shows my bowl and some of the repairs.

Foreground is one I am working on with small pieces of veneer. It was roughed out 8 months ago.

Behind is one with big cracks all over. Marginal. I filled a big one with bondo but don't like the look. below is what appears to be knots but are holes with rosewood splinters crammed into them.

Someday I will saw the bondo out with a hand saw and cram splinters in.

Or not.

 

[David Hill]

Chris, some thoughts on "repairs", (all learned on my own) apologies for being verbose--
I do lots of "fill" or inlay in my turnings. I seem to gravitate to or attract pieces that need extra attention. I haven't posted many pics on this site (am more active on some others).
I like to use a 2 part epoxy that is sold as a "pour on" finish for tables ("famowood" is one, another brand is Parks--about $20), etc.--sold at the big stores--Lowes, HD here-not sure what's in your area. I just mix up as much as I need and get it into the defect. You'll have to use tape to seal the other side--have been using duct tape mostly, but a friend has recommended using a cloth tape.
The epoxy sets up over time, so if it's a crack I'll put it in early while it's a thin liquid, you'll find if it communicates anywhere--so have some paper down or something. If you're vigorous with mixing, let it set some then blow across the surface--most of the bubbles will dissipate. If you wait and let it start curing/thickening it becomes easier to keep in place; you'll have up to maybe an hour. If I want coloring, I mix in whatever mineral I want to use turquoise, malachite, chrysocollite, iron pyrite powder, etc.--be careful to pick minerals that won't hurt your tools---some are as hard as steel (remember the Mohs scale from school?) so research any colored rocks that you might want to use. You don't have to get it right with the first application, the epoxy will stick just fine to prior fills and once cured tools and sands easily. The only down side is that the epoxy takes about 24 hrs to cure--for me that's ok and likely others will chime in with whatever brand they prefer.

 

[Gretch Flo]

I hope this clearly shows my bowl and some of the repairs.

Foreground is one I am working on with small pieces of veneer. It was roughed out 8 months ago.

Behind is one with big cracks all over. Marginal. I filled a big one with bondo but don't like the look. below is what appears to be knots but are holes with rosewood splinters crammed into them.

Someday I will saw the bondo out with a hand saw and cram splinters in.

Or not.

Thanks for the photo, Gretch