Treating knots in pine mouldings prior to hand finishing.

[Not your average framer]

I'm currently producing several hand-finished frames for a paticular client using stacked pine mouldings. I normally manage to avoid using the bits with knots, but on this occasion it has not been possible. For this reason I am sealing the knots with "hard as nails" before finishing over them. I've used this before as it produces a very solid and stable bond, together with a very fast setting time and good sanding characteristics.

I'd be interested to know what others use to solve this problem.

[TheFrameShed]

Knotting compound from DIY shop does the trick as far as stopping any oil or sap leaking from the knot and discolouring the finish. Give each knot 2 or 3 coats allowing to dry in between. Its a thin liquid so doesn't really need much finishing. Obviously no good if you need to fill any holes for a smooth finish. For this try 'plastic wood' filler which is the right colour for pine, easily workable and sets hard enough for a very smooth finish.
All the best

[Not your average framer]

"Hard as nails" is a gap filling adhesive which not only sticks permanently to the wood and fills the gaps, but it is completely impenetratable to the stuff which comes out of knots. It sets rock hard in only a few minutes and sands down really smooth. You can't see where it's been used if it's under a couple of coats of Wickes "Ripple coat".

Prospero has got quite a few of us started on using Ripple coat. It's good stuff and well worth getting and trying!

[prospero]

I usually give raw pine a coat of shellac prior to painting and dab it on a bit thicker over any knots. If they are loose or crumbly, I generally drill them out and fill with wood-putty. I never though of using Hard-as-Nails. I'll give it a go.

[tightmitre]

"Hard as nails" is a gap filling adhesive

Hi Guys, I've "Googled" Hard As Nails and all I come up with is Unibond No More Nails. Same stuff?

[prospero]

Good question. (???)

I use 'No More Nails for joining stacked mouldings as it is stiffer than PVA and will fill gaps and doesn't run.

btw. There was a discussion a while back about Polyurethane glue, re it's strength and gap filling properties. I tried some and it is stong stuff. You have to make sure you wipe off the excess that oozes out as it is a pain to sand lumps out of corners once it has cured. But one thing I don't like about it is the limited shelf life. I had a cartridge of it which I used once. A few weeks later when I went to use it again, it had set hard in the tube. And it's not cheap stuff.

[Not your average framer]

Hi Guys, I've "Googled" Hard As Nails and all I come up with is Unibond No More Nails. Same stuff?

No, it's not the same stuff! "Hard as nails" is a very strong gap filling adhesive, which sets very hard and can be sanded. It makes a wonderful filler and is great for painting over. I haven't been able to get any for a while, as the shop I got it from has closed down, but I think it's still around.

Sorry for not replying earlier, but I've been snowed under with orders and haven't logged on for a few days. Have you tried mixing Polymite powered casin based wood glue into Wickes "Ripple coat"? It will not only fill gaps, but the Polymite will make it rock hard if you put enough into it.

[kev@frames]

not wanting to sound flippant, but there is plenty of pine around virtually knot free - why make extra work for yourself?
I know where you might be coming from, using up pine that's too knotty for regular jobs.
Why not tulip or obeche in the same profile?
Specially if you are busy the time saved would pay for the extra few pence per foot.

when we do need to treat a knot, we just use regular stopper/primer.

[Not your average framer]

not wanting to sound flippant, but there is plenty of pine around virtually knot free - why make extra work for yourself?

Hi Kev,

Normally this moulding is almost completely knot free, but my current delivery is full of knots. I don't think I have any grounds to return it, as I don't think that knots in pine is classed as abnormal and the number of knots is not specified.

[kev@frames]

unlucky, Mark
it'll be someone elses turn next time, not that it helps much

what about a spray primer/stopper if you want to treat a batch, just to save time?

Doing pine frames has caused us more complaints in general than pretty much anything else over the last 15 years. Customers either accept, love them or hate the knots. We even made sure our pine chevrons on the board have a thumping big knot in them just to make sure they know what they are getting.

[Roboframer]

I'd be interested to know what others use to solve this problem.

I don't stock unfinished pine - problem solved!

[framejunkie]

I don't stock unfinished pine - problem solved!

ditto
It's such a PITA. When i started up and was trying to ge tby with not enough customers i made a batch of White box frames and used builder's grade softwood. Took ages to get a decent finish on them, then one or two of the knots were showing through as nasty stains in the gesso about 6 months later and i had to remake the whole lot using some decent timber. (the customer was not only my best at the time, but also a good friend)