Filling Slabs with Resin

[roopaw]

I've a number of large holes to fill with clear resin in my Jarrah slabs. I've been told Araldite is the best to use, but this is looking too expensive. Is 2 part epoxy the same, is there a particular epoxy I should be using for this job?

[soundman]

I personaly wouldn't use araldite as it tends to go quite yellow with age, that wouldn't be so much a problem if you were tinting it black or something.

I be inclined to look at one of the pouring lacker/epoxies ( names don't come to mind just now) they stay cleer and are probably cheaper than buying little tubes.
You will need to make sure the back of the void is well sealed or it will just run out the back.
cheers

[leighd]

if u have alot of holes u can use west systems epoxy and use the cotton gap filler with it. Then u can add oxide colouring to what ever colour u want. Chocolate is a good colour for dark jarrah.

[DanP]

Roo,

Did a Red gum burl clock and I filled large holes in it with casting resin that I got from Bunnings. Came up a real treat.

Make sure you cover the backs of the holes with tape or you will be pouring forever and just end up with a puddle on the floor. I used syringe (no needle) to accurately measure the catalyst (also from bunnings) and then sucked it up into a big syringe and squirted it into the hole. Clean and easy. Throw the syringe out when done. They're cheap as chips from the chemist.

Dan

[TOMARTOM]

I use west system mixed with a little powdered graphite to give it the "gum vein look". Works a treat.

regards tony

[ubeaut]

Clear casting resin is definitely the go. But rather than match the colour or hide the fault make a feature out of it/ Embed stuff in the resin. A spider, fly, marble, bits of cotton thread, gold leaf, gravel, etc, etc.


You can have great fun with it.

Cheers - Neil

[silentC]

I had an experience with this stuff on the weekend that might help. The brand is Norglass and it's a clear polyester resin called Casting Resin.

I've got some blackbutt with a few deep gum veins that I wanted to fill. I mixed up 100 mil of the stuff with 1% catalyst (using a syringe like Dan suggests). First tip: if it's a bit cold, use more catalyst and make sure you mix it well. Mine took most of the weekend to dry and is still a bit sticky in places.

I poured the stuff into the vein and let it build up so it was proud of the surface. I went way and when I came back, the level had dropped below the surface. There's no puddle underneath so I can only assume that it has seeped into the vein. So I guess it would be a good idea to seal it first. Shellac maybe?

Third problem, although I spent ages blowing on it to get rid of the air bubbles, after I left it a few more rose to the surface. These obviously came out of air trapped deep in the vein that formed over time. I don't know what to do to stop this - maybe sealing would have helped here too.

I've now got the problem of topping it up without trapping dust etc in between. Either way it's going to be a second rate job and I'm a bit annoyed about it.

[ubeaut]

Use catalyst at rate recommended by the manufacturer.

Silent - Yours is probably dry it is most likely the surface stuff that is tacky. Wipe it off with the correct thinner and you will most likely find the stuff underneath is rock hard.

:eek: Warning:

• This stuff will follow any track it finds inside a piece of timber, the smallest pin prick will provide an escape route for it.
• Avoid moisture like the plague, it hates it (if the timber is green don't waste your time).
• Don't leave it until it has heated up and started to go off.
• This stuff gets very hot and can cause the odd problem or two or three in timber, best if you stay with it for the possible fun and games.

Tips:

• Get your mixtures right and make sure it is completely mixed before using it.
• In most cases a syringe isn't necessary, just drip it into e crack etc and it will find its own way. The syringe could create more problems than it's worth.
• Learn as much as you can about the product and its charicteristics before using it. Most products like this aren't for home hobbiests they are made for professionals and often need a degree of skill to make them work right
  
• Experiment with it on a scrap piece of timber before jumping in boots and all on the good stuff. You could save yourself a bit of heartache, a lot of anger and the odd tear or two.

Cheers - Neil

[silentC]

Thanks Neil.

Use catalyst at rate recommended by the manufacturer

They say 1% to 2% on the label. I put 1 ml in my 100ml batch but it took ages to go off, so I think I would put 2ml in next time. They do say to use more if you want it to go off faster or in cold weather, I presume they mean to use closer to 2% than 1%, not more than 2%.

What do you think about sealing it first? Waste of time? I considered a coat of shellac or something but ended up jumping in boots and all - I'm like that. Fortunately it's not a critical piece. I think it will scrub up OK - I scraped it back a bit and you can see right into the vein. Clear as glass.

roopaw, if you follow Neil's advice and read the label, I think you'll find this is the stuff to use for what you want.

[bitingmidge]

Just a note for those using epoxy:
DON'T vary the ratio of resin to hardiner, you'll upset the chemical reaction and it won't go off.

It's Ok for polyesters, but NOT for epoxies, and no, not all two-pack mixes are the same!.

There's been a bit of a thread on bubbles fairly recently, and there are lots of reasons for them other than the one that is the bane of my life: as air trapped in the timber expands due to the heat of the resin going off (or the ambient temperature rising) bubbles form and just conspire to bugger up the job.

I leave stuff in the sun for a bit before coating it, so that the surface temperature is quite a bit warmer than the air, the bubbles don't form and we all live happily ever after. (Specially the dog, who doesn't get kicked!)

A heat gun or hair dryer would probably do the same.

Cheers,

P

[AlexS]

Just a bit to add to the good info above. I used an epoxy casting resin called araldite M, from Meury enterprises in Sydney. This is NOT the same as araldite adhesive, although I suspect it is similar.

The info about it going into every little crack is spot on. you need to ensure that all possible leakage points are blocked. I used masking tape on the back, with scrap plywood clamped to ensure a seal.

Use the recommended proportions, and measure accurately. If you don't get them spot on, you may wait a long while for it to set.

I've sucessfully used a hot air gun to release air bubbles, and have heard of a blowtorch being used.

The resin will shrink a little, and can be sucessfully topped. However, I find it easier to build up a 'dam' around it with string held down bu masking tape. This lets you overfill the gap and then plane it down later.

Araldite M sets clear and seems not to yellow. You can embed objects in it, and I think you could pigment it, although I've never tried it. I've also heard of people using food colouring, but try a bit of scrap first.

I've also used techniglue coloured with pigment as a feature. This worked well, and you don't need much pigment. This gives an opaque coloured featured.

As always, do a test piece first.

[leighd]

with west systems u can just get a pump it for it which is about $25 i think. U just put the pumps on the resin and hardener and 1 pump from each will give u the right mixture then just add filler till u get the consistancy u want.

[soundman]

Its also very worthwhile reading the teck info in detail with these products.
One of the casting resins I used was very sensitive to the tempriture & humidity at time of application.
too cool & it wont flow well too hot & it flows too well & you get no film thickness. can't comment on the humidity effects.
A bloke I knew did a lot of clocks & posters, he had an airconditioned room built to control temp & humidity.
cheers