Bonda wood hardener - recommended. :)

[quickshift]

I thought I would try using Bonda wood hardener on the speakers I'm building - Shin mentioned it and since he seems to know roughly what he's on about I thought I'd give it a go.

Anyway... Bloody good stuff - it's a very thin liquid resin - the viscosity or water or thereabouts, it soaks right into MDF and really does change the properties. I sprayed it on using a trigger pull sprayer - no problems although it took about 4 days to wear off my arm where I accidentally sprayed myself....

The most obvious effect is how much better the finish after sanding down is, very smooth indeed - almost like plastic and I didn't get the typical furry finish after priming the cabs with the first coat of MDF primer either. It did however take a lot longer to sand the cabs down because the MDF is that much tougher.

I may use a couple of thin strips of MDF to test how much stronger it is by seeing how much mass is required to snap a treated bit Vs an untreated bit.

Anyway, just thought I would pop that down - Bonda is deffo worth a try.

[ShinOBIWAN]

Great Stuff Mike,

Your the first that I've heard from who's tried this and it sounds like you've got the same results I did, which is always good.

The original thread along with a UK link to purchase this stuff for anyone else interested:

A solution to MDF expansion on joints, translams etc.

Its also dirt cheap for the hassle it saves.

[catapult]

Interesting guys. I'm going to try to find something like that. A quick Google turned up a couple of products available here in the US.

Minwax has a solvent-based one, should be able to get it in most paint stores:
http://www.minwax.com/products/woodmaint/hardener.cfm

PC Products has a water-based one:
http://www.pcepoxy.com/woodproducts/woodpetrif.asp

Does the Bonda have a solvent (acetone?) smell?

[Rodeodave]

I suppose you are using this on MDF you'll build a speaker with.

Do you use it before the parts together or afterwards?
What kind of glue are you using? Seen any reaction between glue and the wood hardener?

[ShinOBIWAN]

Originally posted by Rodeodave
I suppose you are using this on MDF you'll build a speaker with.

Do you use it before the parts together or afterwards?
What kind of glue are you using? Seen any reaction between glue and the wood hardener?

Yes with MDF here.

Definitely use once you've finshed construction. You'd almost certainly have issue's glueing surfaces together since after you apply the stuff the treated surface is non porous.

I use regular weatherproof Evostik Resin W glue. No reaction whatsoever with the glue.

[quickshift]

Originally posted by catapult
Interesting guys. I'm going to try to find something like that. A quick Google turned up a couple of products available here in the US.

Minwax has a solvent-based one, should be able to get it in most paint stores:
http://www.minwax.com/products/woodmaint/hardener.cfm

PC Products has a water-based one:
http://www.pcepoxy.com/woodproducts/woodpetrif.asp

Does the Bonda have a solvent (acetone?) smell?

It doesn't smell sweet enough to contain acetone, it's more like thinners or solvent based varnish, deffo solvent based.

I would think the minwax product is pretty close to Bonda, it doesn't say it uses the moisture in the wood to cure but whether that makes a difference or not, I don't know.