Epoxy as a filler question

[Aragorn]

Please can someone tell me if I can use epoxy as a filler for large areas?

I want something that will set completely clear (or as near as), without voids or bubbles, and that can be worked (after it has set) to a smooth clear finish.
If such a thing exists, please let me know. I'm imagining this is how epoxy can be used, but I have little experience of using it.
Also, a supplier for whatever material you think is best?

TIA

 

[J.A.S]

Aragorn,

I can't answer your question myself, but when I was looking into using epoxy, I found some useful tips and guides, including advice on filling and fairing, on West System's site.

Hope this helps.

Jeremy

 

[johnelliott]

Araldite will do for this job. Use the slow setting one as the rapid is too soft. To make it translucent you will need a hairdryer or heat gun. Use it to warm the tubes before mixing, then use it again to drive out the air bubbles (they are what cause the resin to go cloudy when it's mixed). After filling the area use the heat gun again to drive out the bubbles which will exit the pores in the wood.

How large is large? If tubes of Araldite aren't big enough then you will probably need to buy from the West system, look for a casting resin

John

 

[Aragorn]

Thanks for the link J.A.S. and for the heat gun tip John. I'm sure that's going to come in handy.
Large is a volume of about 20x600x600mm, so that'll be two or three tubes of Araldite?? :shock:
Hmm, perhaps I should get on to Damien Hirst and find out how he set that cow in formaldehyde...

 

[Chris Knight]

Aragorn,

As John says, how large is large? Contrary to his view, I would go with West system rather than Araldite on both cost and transparency grounds. I bought a "small" quantity of the West system from a boat builders' supply house for about £13. I put it in inverted commas because it may have been small for a boat builder but I am still using it after three years - it was probably about 500 to 700 cc) .

It does need a gentle application of heat (eg hair dryer) and two or three applications (depending on depth filled) to completely avoid bubbles. It is usually mixed with a variety of fillers to do jobs ranging from gluing to filleting but if your job can be laid flat then unthickened ( and extremely transparent) glue would work.

The basic fillers are finely ground glass so that properly wetted, they maintain transparency quite well in fact.

 

[jasonB]

I've used epoxy to fill cracks in turned work but used a metal powder to make it look like silver. Just work your way through the grits to get a polished finish.

http://photobucket.com/albums/v156/jaso ... iveAsh.jpg

For the amount you need clear casting resin - the type used for paper weights - would be the best way to go.

I get my resins from Tiranti, they have a very good web site and delivery is usually next day. Can't get a direct link to work but goto products, resins, polyester resins, clear is at the top.

www.tiranti.co.uk



Jason

 

[Chris Knight]

Aragorn,

That is BIG! I second Jason's suggestion. I once cast a paperweight with a disassembled watch inside it that came out quite well, it was about an inch thick.

 

[Aragorn]

Jason/Chris
Many thanks - that's just the stuff I need.

Any idea how to work out what size I'll want?

 

[jasonB]

Polyester resin has a specific gravity of 1.13. therefore 100g of resin has a volume of 88.5ml.

I think you will need 7.2lts or 7200ml (if 1lts equals 100mmx100mmx100mm 6x6x0.2)

7200 / 88.5 = 81 x 100g = 8.1 kg

Buy 10kg to be safe and don't forget the catalyst (hardener)


Anyone want to confirm my figure, the SG is correct.
Jason

 

[Aragorn]

:shock: Jason, you're a star! Thanks very much

 

[mahking51]

Aragorn
Please be VERY aware that if mixing resins in this sort of quantity there is a BIG prolem with the mix heating to dangerous levels and catching fire/ melting containers.
See the West manuals for ways round the problems.
Regards
Martin