Sap/ Knots in skirting

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JimWoodwork1975

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Hi, what's the best stuff to block knots and sap in pine skirting before painting (with Crown Trade).

If it could also be used on a small water stain on a painted ceiling that would be ideal.

PS I know it's probably Zinsser but I'm not sure which one will do both jobs: Bullseye, 1-2-3 or BIN?

Cheers

Jim
 
Just an aside. I undercoated the painted a few new door frames/arcs in my house and forgot to do the knots. Not particularly sappy but sure enough 2 months later.... there they were.
Rather than rub down properly I sprayed some mould block I had spare. Dried and lightest of sands to blend in and repainted eggshell. Just to see.
Not reappeared best part of a year later.
Not a recommendation. Just an observation. :D
 
I think normal knotting stuff limits what you can put on top... oil based only IIRC. That's maybe just the stuff available up here so read the label. There was a reason I ended up using BIN (it blocks just about everything) instead as it'll take anything and, with the lightest of sanding, gives you a very smooth surface to work on.
 
I have a painted pine fire surround that has constantly leaked sap despite me putting loads of knotting on it but it seems to have stopped since I used some aluminium primer on it, don't know if it's coincidence or if the primer did the trick.

Thinking about it, it was of course worse when the fire was lit, maybe the aluminium primer reflects the heat or something.
 
Just dug my unused bottle of Rustins out to remind myself why I never used it. It says it has to be sealed with an oil based primer or undercoat (to stop it from discolouring the top coat) before putting anything water based over it. Back in the cupboard it goes then ;)
 
katellwood":1r5hbp8w said:
Quickben":1r5hbp8w said:
Another vote for Zinnser BIN. It's shellac based.

So is Knotting


Not all knotting products are shellac based, only the better ones. Zinnser has the added benefit of being a very good primer\sealer as well.

It does have one draw back, though: it's hell on brushes...
 
I must admit not done a great deal of unsorted softwood work recently, used Wickes knotting with an oil based primer and topcoat.

The biggest issue I had was cleaning the brush, tried white spirit and thinners no luck so one brush in the bin.

will definitely try Zinnser next time.
 
katellwood":xjc1vtex said:
I must admit not done a great deal of unsorted softwood work recently, used Wickes knotting with an oil based primer and topcoat.

The biggest issue I had was cleaning the brush, tried white spirit and thinners no luck so one brush in the bin.

will definitely try Zinnser next time.


Zinnser is the same regarding cleaning the brushes. My mate's a painter decorator. He just leaves the brush in the tin and makes sure it's sealed properly. Then bins the brush with the empty tin.
 
Every time I buy B-I-N Zinsser primer the joker in my local decorator centre always says "B-I-N Zinsser, bin the brush!", it gets very tiring......
 
katellwood":2brhmgzq said:
The biggest issue I had was cleaning the brush, tried white spirit and thinners no luck so one brush in the bin.

Methylated spirit cleans knotting solution since it's usually just a very heavy shellac.
 
I have just done a stretch of skirting , Plenty of knots so drilled them out and plugged holes with clean wood filled and sanded
 
Make yourself a knotting pot if you've got a spare few minutes.
1be8c80b669d7888e256dc5102ae4453.jpg

Always ready to go and you never need to bother washing out the brush

Sent from my SM-G960F using Tapatalk
 
Paint over the ceiling stain with gloss then go over it with emulsion, worked for my stain.

Pete
 
katellwood":2luv2kjq said:
Racers":2luv2kjq said:
Paint over the ceiling stain with gloss then go over it with emulsion, worked for my stain.

Pete

will the emulsion key to the gloss or do you create a new key

I just painted over the dried gloss, no problems at all.
The stain came back with emulsion, it was a rusty water stain from an old leak, the gloss blocked it completely.
I think the stain block paints are just gloss sold at a higher price.

Pete
 
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