Stopping up cracks in myrtle?

[BluntTool]

Hi All,

I would appreciate some advice if you (collectively) don't mind.

I have a lovely piece of Myrtle, which I am hoping to turn into a wall-mounted coat rack. It has a few knots and cracks which I would like to fill (?stop up). I think they add to the character of the wood, so I don't want to conceal them but ideally would like to fill (stop) them with something clear. My plan is to finish with shellac, and I think stopping the knots might protect them from the finish (I don't want the shellac to pool in the bottom while I'm finishing or create an uneven finish in there compared to the rest). I can't seem to find a stopping product with a clear finish though. Epoxy resin was recommended to me today, but this sounds potentially fraught with danger for a junior woodworker such as myself.

An alternative could be to not fill the knots and cracks, and finish the piece with hard burnishing oil, but I'm not confident of achieving the result that I'm after. That's not to say I'm confident of achieving it with the shellac either, but think i have a better chance this way.

Does anyone have any thoughts on this process?

Many thanks,

Andrew

[Christos]

I have used Epoxy to fill cracks and gaps. I added a black dye to the mixture.

If you use epoxy then ensure the hole is covered from the other side. I have used plasticine and once dried(cured) I removed the plasticine and filed the other side. Try not to over fill as it is just more work to clean up. It can be sanded but I used the edge of a scraper to clean up. You can also use a chisel as a scraper for smaller holes.

Well ventilated area also recommended.

I might suggest trying a sample with the Myrtle with different coloured dyes.

[BluntTool]

Thanks for your advice Christos.

A couple of further questions come to mind.
If I don't add a dye, will the epoxy dry clear or turn opaque? Will sanding directly onto the epoxy affect its finish?
What type (brand) of dyes would you recommend?

Thanks again.

Andrew

[Arron]

A couple of further questions come to mind.
If I don't add a dye, will the epoxy dry clear or turn opaque?

Depends upon the brand - they are all different formulations. BoteCote will be cloudy, West System is clear.

Will sanding directly onto the epoxy affect its finish?

No. Fine sand, then coat with varnish or whatever, and the scratches will disappear. Magic really.


Personally, I'd use polyester resin rather then epoxy. Reason is its cheaper, less harmful to your health and easier to sand, being a little softer. Casting resin, as sold by Bunnings, is a good source.

This issue of filling with a clear substance is something that has been raised before without any clear resolution. All the options are pretty second rate, which makes one wonder why a better product hasnt been invented. In the US you can buy Crystalac, but not here. The problem with either epoxy or polyester is that they are significantly harder then the timber, so be careful sanding. You can fill with shellac if you dont mind doing endless coats.

cheers
Arron

[Dengue]

What black dye would you recommend for epoxy like Techniglue - Feast Watson ProofTint Black Japan? India Ink or fine graphite powder?

Doesn't this epoxy clean up with water if you overfill and spread, but you do it before it cures?

[Arron]

Doesn't this epoxy clean up with water if you overfill and spread, but you do it before it cures?

I havent used that product so cant be sure, but I'd still expect to have to do some sanding to get a perfectly flat surface.
I do note that its marketed largely as an adhesive, with its filling capabilities incidental, so it wouldnt be my first-choice product.

cheers
Arron

[mic-d]

How big are the cracks and knots? I've used epoxy tinted with oxides in the past for larger holes. For smaller repairs I use shellac sticks in various colours, melted in with a soldering iron. I was given a small piece of what I thought was a water-clear shellac stick a while ago which did a good job of small flaws like dents and tearout. When I was running low on it I had a look around for more and found a few contenders such as amber shellac glue sticks,(if you want amber), a few different colours including a water-clear shellac stick here...

But the one I'm pretty excited about trying are these sticks (towards middle of the page) called 'burn-in sticks' (a term I have never heard before - suspect it refers to shellac sticks too, since you 'burn' them in). These ones are made from a modern resin which replaced their earlier shellac sticks and are apparently superior to shellac. The mob I linked to have the most comprehensive set of colours I have seen, including a few transparent sticks. There's a video here.

[mic-d]

What black dye would you recommend for epoxy like Techniglue - Feast Watson ProofTint Black Japan? India Ink or fine graphite powder?

Doesn't this epoxy clean up with water if you overfill and spread, but you do it before it cures?

You can use FW Prooftint black, but I wouldn't use FW black Japan. You can also use black oxide pigments (I've used concrete colours) you only need a very small amount or it will affect the curing. No, techniglue cannot be cleaned up with water. You can clean up tools with vinegar before it cures, like most epoxies I guess, but I would not use it to tidy up the work, it will quench the polymerization wherever it contacts leaving you a bigger mess to clean up. Leave as little to tidy up as possible and do it after it cures.

[Christos]

I have used the West System epoxy with Feast Watson dye. I have also used some black oil based craft paint on a test piece but did not get a black enough colour. Did not keep the test piece.

[BluntTool]

Thanks all for the advice and discussion so far. I'm very keen to learn, but trial and error can only get you so far!

I will try to attach a couple of pics of the piece to give an idea of the size of the cracks. One in particular is a decent size, and about 10mm deep.

I dropped in to the local fibreglass shop yesterday and they recommended (and subsequently sold me) a product called Glass Coat. I believe it is an epoxy resin, but is marketed as one for indoor use and use with timber. It should dry completely clear, and seems ideal for what I want to do, but is anyone familiar with it?

One suggestion that keeps coming up is to add a dye of some sort to the resin. At the risk of sounding quite stupid, why would you want to do this? Presumably you would choose a colour to match the underlying wood, but then why not use something clear and let the underlying wood reveal itself? I can understand filling dents and subtle defects this way to conceal them, but would you fill cracks/knots this way too? I'm just a bit confused as to what the advantage would be.

Andrew

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[mic-d]

Thanks all for the advice and discussion so far. I'm very keen to learn, but trial and error can only get you so far!

I will try to attach a couple of pics of the piece to give an idea of the size of the cracks. One in particular is a decent size, and about 10mm deep.

I dropped in to the local fibreglass shop yesterday and they recommended (and subsequently sold me) a product called Glass Coat. I believe it is an epoxy resin, but is marketed as one for indoor use and use with timber. It should dry completely clear, and seems ideal for what I want to do, but is anyone familiar with it?

One suggestion that keeps coming up is to add a dye of some sort to the resin. At the risk of sounding quite stupid, why would you want to do this? Presumably you would choose a colour to match the underlying wood, but then why not use something clear and let the underlying wood reveal itself? I can understand filling dents and subtle defects this way to conceal them, but would you fill cracks/knots this way too? I'm just a bit confused as to what the advantage would be.

Andrew

You've got the right idea, just the wrong situations. It's better to fill minor dents and subtle defects with clear so the underlying wood can reveal itself and the dent disappears. With larger holes like your knots, if you fill them with clear (and there's no law against that) it'll just look like a big filled hole. When you add a dye to colour match it you camouflage the hole by making it look like a gum vein, resin pocket or just the darker wood in a knot.

[Dengue]

What mic-d said is spot on

Also, you will never really match the colour of the timber or the cracks, knots etc, so use something that looks really good. I have noticed the black coloured expoy used on the big slab jarrah tables in one of the display rooms in Margaret River, WA -it looked spectacular, and I think it will look great on your piece of timber too.

Attached is a product sheet about colouring Techniglue CA two part epoxy - hope this helps

[BluntTool]

I think the light may have just gone on!

Thanks again for the info and advice. Much appreciated! I think I will try some black dye of some sort, like you suggested Dengue, and re-post some pics of the finished product when I finally get there. Hopefully I will have something worth showing!

Cheers.