Thread: Titebond 3 turns green on Blackwood

Prolly stop wippin git off with water. It just gets spread thinly around. Wait till its nearly dry and scrape it off. Not sure why its going "green"" Maybe absorbing bit of tannin out of the wood?

In Australian Wood Review #47, Richard Vaughan found that all the crosslinking PVA glues he tested made blackwood go green. It can be sanded off but leaves a visible glue line. You might want to use a non-crosslinking PVA or epoxy.

Cheers
Michael

News to me, never seen it happen on any blackwood jobs I have done.

I've just always wiped with a clean wet rag, then if any green tinged areas are left once the timber is dry I hit with sandpaper.

I definatly know TB Original doesn't go green on Blackwood, and I don't think I have noticed TB III do it either. I always wait till its dry these days and take it off with a sharp chisle or scraper. If I do wipe it, I don't use water, it just soaks further into the timber. I might check some tomorrow. I am just doing some glue tests at the moment. These are Tassie Blackwood 250mm Lx 40W x 18T basic lap joint. Tested is a local bottled PVA Woodlok, Titebond Original, AV XL Plus water resistant crosslinked PVA, Selleys Aquadhear External and Sika Polyurethane 30 min.
All glued 50mm of basic lap joint left for 48 hours and then put in the vise and snaped off. Very basic test, I am just looking to see if the glue lets go or how much timber it takes with it when it goes. All the PVAs took almost total wood surface with them ie the wood failed not the glue. The only one (as expected) was the polyurethane which did not take any wood with it. The glue failed but I wouldn't use it in a standard furniture joint anyway. The only one of the PVAs not to take 100% of the wood surface when it went was Titebond Orig but maybe that piece of timber didn't get full surface contact (I thought it did) I might check it again. I am going to test tem again with a diferent joint. TBOriginal what about $16 for a 750ml bottle (TB III $19), Selleys about $12 - 14, AV XL plus $15/ltr, Woodloc $7/ltr.
Oh and didn't notice any green.
I ran out of TB III a while back and haven't bought any more. I actualy found it too runny or too fluid.

Originally Posted by tea lady

Prolly stop wippin it off with water. It just gets spread thinly around. Wait till its nearly dry and scrape it off. Not sure why its going "green"" Maybe absorbing bit of tannin out of the wood?

Good call on both Bad mistake to wipe glue off with water full stop. Let it half dry and scrape like TL said. And Black wood is notorious for going green with TB111, just use original. And as TL pointed out its just the tannin reacting with the cross linking.

Thanks guys,
I'll try scraping the glue off next time instead of wiping it. Thanks for all the help.