Filling pine knots and dings - wisdom needed

I've been doing a lot of pine recently. Nice stuff - siberian grown baltic pine. Tight rings with few knots and next to no sap at all.

Its not much by any commercial scale - but I do use 30 to 36 metres of it cut down in slats and other things... which leaves me with 120-odd metres of filling and finishing to do a week.

Up to now its been Polyfilla Trim and doors.

I've absolutely no complaint about it at all. It dries fast, sands well and does a good job. The only real negative is the fact its white. The other is price at ~$13 for 330ml. Under painted things its no problem, but I've a few jobs now where the client has wanted the wood to be sprayed in nitro, poly or shellac.

Looking around, I found a tip to use auto body filler. Car bog! It can be tinted so to match the pine quite nicely. Its bulk, cheap, dries hard and fast and is completely sandable.

Does anyone have any tips or comments for bulk filling of timber knots and holes that might be used in larger workshops? I was thinking of those rustic pine furniture sellers - what do they use?

cheers!

I dunno about pine, but for stained doors & windows made of eucy, cedar or PNG rosewood we simply tint auto bog to match any existing 'features' or, for clear timbers, near match the final colour. :)

For patching tear-out that I miss while milling the timbers (it's hard to inspect every piece perfectly when whole days are spent milling. :- ) I make a 2:1 paste of appropriately coloured timber-mate and Titebond III PVA. It's not invisible, but done well can look quite natural.

Small dings in softwoods are just steamed out with a household iron.

In my last furniture making job we were big users of builders bog tinted with iron oxide powder (brown or black) that's usually used for coloring cement/grout. It holds up splendidly, even on an edge/corner, and comes back to a nice shine under finishes...even oil. It doesn't shrink but I still overfill a little just to be sure and save having to go back over it again and the quick, adjustable, drying time is fantastic. You can even trowel it on in wide swathes if need be.

It can be a pain to use solo on big jobs as it can harden before you're finished, but if you mix up a big batch of tint and putty then only mix the hardener into smaller portions you'll get consistent color and won't waste as much.

The cons with it are:
- it gets into open grained or only roughly sanded timber and can cause colored patches if you're not careful;
- it clogs up sand paper fairly quickly, so I use an old 80 grit belt on a belt sander to take the majority of the excess off first;
- usually it's great, but sometimes it doesn't hold too well in teeny-tiny little holes (gum veins) and specks can pull/fall out with vibrations of sanding;

Looks like a big 2kg tub of Timbermate is on the cards. $35 seems a great price for me and it comes in "pine". ;)

I'll also call past the car store and get some bog. :)

Opinion: I've always found the "pine" Timbermate to be too pale on Radiata at least. "Hardwood" is a much better color match to my eye. (The colors fade and go pale when dry.)

I've used a few different brands of the builders bog available from the big green shed and haven't had trouble with any of them...just a note incase of a significant price difference at the auto joints...

Have fun smearing goop around :D

Oh oh oh...also...in and around knots where the natural color is usually darker (not sure of your timber colors here but bear with me) chuck something darker like walnut Timbermate in them. The much much paler "pine" and "hardwood" colors will stand out like the proverbial dogs' :)

A certain degree of color matching/similarity will be a huge difference between something that is simply filled/smooth and something that looks good.

I've also had a bit of success mixing different colored Timbermate together. If you're clever and don't mix them together much, you can get a swirl/streak thing happening which looks lovely and a little more natural, even in minute patch ups.

Anyway...I should go do something about this keyboard diarrhea I seem to be suffering ;)

I've never seen th epoint of "builders bog", its more expensive that automotive filler and I doubt that it is any better quality.

I have used automotive filler to fill holes in timber for years, if colour does not matter you will not find a filler that is more durable or sticks in the hole better ..... except for epoxy.

Another option is "plastibond" ..... it is pretty much the same resin as bog but it has more resin and less filler ......

Both bog and plastibond can be tinted ..... but ya have to be carefull about what you tint with........ some things will stop it going off.

Of course both bog and plastibond are made on the same resin commonly used for fibreglass ... polyester resin.

If course you can use polyester resin clear or with a filler of your choice.

Lots of people fill knots with tinted poly resin.

One tip for any filler is ..... sand and apply a coat of sanding sealer before you fill the hole.

cheers