PVA wood glue and saw dust

[Slowhand]

I know it’s a very well known technique to fill gaps, cracks with a filler which matches the wood, but when I mix PVA with a wood dust say lime , cherry or beech the mix always dries darker than the original wood dust. The only time the filler is a matching colour is when there’s hardly any PVA there and the mix is too crumbly to be much use. My friend in my wood working group has the same problem. Tried  different UK manufacturer’s but to no avail. Any suggestions please?

Edited May 13, 2021 by Slowhand
Typo

[Jaager]

Is your type of PVA - yellow - which I prefer for wood to wood - or white PVA. 

The white seems the be water clear when it polymerizes.  The yellow is clear amber.

If you are using white - the darker color may match the wood when wet - which is the color it will be when a clear coat finish is applied.  (shellac for me). 

If you do a test - same wood - plus a patch with white PVA - and use you final clear coat on it, is the filler still darker than the wood?

[Justin P.]

I use white PVA wood glue for the reasons stated above.   I generally try to make a 1:1 ratio and then dilute with water which can help with the "too dry" to use issue.

[mtaylor]

Same question as Justin.  I do it slightly different by mixing the white pva glue 50-50 with water. Add sawdust to the consistency needed. Or add the mixture to the sawdust....  it depends on preference.

[Ryland Craze]

I also mix the sawdust with white PVA glue.

[Slowhand]

Ah interesting. I have always used white glue it appears to be the default in the UK.

 

When I mix the wood dust with neat PVA it initially matches the wood then darkens significantly as it dries. The final finish Danish or wipe on poly makes no difference to the mismatch between the wood and the filler. 
Off to the shed to try a 1:1 mix plus water.

[vaddoc]

I think I ll contribute my 2 c

I tried the PVA-wood dust mix but couldn't make it work. Too dry, too crumbly, did not sand nicely. I much prefer purpose made fillers.

I tried mixing Elemers filler with wood dust. Did not work.

In my current hull I used Beech and I tried Osmo filler that comes in various wood colours. Very nice to use, only issue it dries really fast. Yesterday, I did a bit of testing,

This piece of wood has a groove filled with filler. The left side has 2 coats of a water based sanding sealer. The right side has pure Tung oil on. Both were smoothed with steel wool. On the Tung oil side, the filler is barely visible on the non-forgiving photo but it is completely invisible actually looking at it.

 

 

[Charles Green]

I'm in the process of of filling a small bit of damage on walnut.  I've got regular Titebond III and Titebond II Dark Wood Glue on hand.  Mixed with sanding dust from the part being repaired, the TBIII dries too light and the TB Dark dries too dark.  I'm experimenting with mixing the two glues to get the shade I want.  A 50/50 mix is close.  I'll try TB II, one part and TB III, two parts.  Sooner or later, it looks like I'll get what I want.  With sanding dust taken from the part being filled, this method should work for any color of wood.    

[Slowhand]

On 5/14/2021 at 3:29 PM, Slowhand said:

Ah interesting. I have always used white glue it appears to be the default in the UK.

 

When I mix the wood dust with neat PVA it initially matches the wood then darkens significantly as it dries. The final finish Danish or wipe on poly makes no difference to the mismatch between the wood and the filler. 
Off to the shed to try a 1:1 mix plus water.

Yes this worked a treat, 1 to 1 PVA water then added dust to make a sticky mix. thx everybody

Edited May 30, 2021 by Slowhand
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