Sanding door frames and skirting boards help

[JohnDoe123]

Hello,
I am currently preparing to paint my door frames and skirting boards and I have read everywhere that I will need to sand or strip off the paint first.

So I have bought a electric sander as I have a lot to do!

I've just started and using a 60 grit sandpaper. I started on the door frame and did a bit and got to this stage but I'm not sure if this is enough. Everywhere says I have to sand it to get a 'key' but how do you define that?

Here is a couple of pics.

This is before sanding:



and this is after:



As you can see the 'after' pics still has some of the dark yellow bits which is still the gloss because it is not totally flat. But if I need to totally eliminate all the yellow bits, it will take ages and ages!

Please advise ...

 

[thebug]

You dont really need to sand it all off, for me p60 is a bit overkill for what you are doing as it will just start to rip chunks out the paint, try p120.

Keying the paint is just a light rub to take the shine off so the undercoat can bond to it

 

[JohnDoe123]

You dont really need to sand it all off, for me p60 is a bit overkill for what you are doing as it will just start to rip chunks out the paint, try p120.

Keying the paint is just a light rub to take the shine off so the undercoat can bond to it

Thanks

I did start with 120 grit but it hardly seem to make much difference but then again I don't know how much I needed to sand.

So from the pictures, can you tell if that is enough sanding before I apply the undercoat? As I said the bits of dark yellow in the 'after' pic is still the previous gloss and is still shiny because the sander hasn't reached it due to the ridges.

 

[WabbitPoo]

Should be fine as is. Just make sure you undercoat next. Assuming you are opting for white instead of that awful yellow, you may need two coats of u/c to cover it before you gloss. Don't rely solely on gloss to cover such a strong colour.

 

[joe-90]

I wouldn't gloss it if I were you, it looks like it's been painted by a comedian.

I'd use 80 grit and a belt sander with speed control. Set on slow speed and get rid of the bulk of the brush marks. Then oil undercoat and satin/satinwood finish.

 

[JohnDoe123]

Should be fine as is. Just make sure you undercoat next. Assuming you are opting for white instead of that awful yellow, you may need two coats of u/c to cover it before you gloss. Don't rely solely on gloss to cover such a strong colour.

Yeah, going to be white - definitely not that yellow!

I was going to prime it first with Glidden Trade Acrylic Primer, then undercoat with Johnstones Aqua undercoat and finally Johnstones Aqua Gloss White.

One coat of each should be enough?

I wouldn't gloss it if I were you, it looks like it's been painted by a comedian.

I'd use 80 grit and a belt sander with speed control. Set on slow speed and get rid of the bulk of the brush marks. Then oil undercoat and satin/satinwood finish.

I did think about satinwood then read about the johnstone aqua gloss and it sounded good. It's probably too late to change now as the paint is arriving tomorrow! Do you think my above combination will be good enough or will be become a mess when I slap it on?

 

[joe-90]

You'll find that Aqua is very difficult to use. Satinwood and oil undercoat would have been a doddle in comparison.

 

[JohnDoe123]

You'll find that Aqua is very difficult to use. Satinwood and oil undercoat would have been a doddle in comparison.

So are you recommending oil based satinwood or water based? The reason I chose aqua gloss was because of the non-yellowing properties unlike oil based paints. Is Aqua really that bad?

Don't know what to do now. Shall I open those 5 litre cans of paint only to find out they are a pain and I've wasted my money or send them back for a refund/exchange?

 

[joe-90]

It's hard to say what to do. Satinwood isn't as bad for yellowing as gloss. I love Aqua but it's not easy to apply. Water based paints are prone to brush marks if you are not used to them whereas oil based satinwood is pretty much foolproof. See what the other guys think.

 

[Jimmy321]

If you are using water based paint and having trouble using a brush you should try a gloss roller, try to spread it thin.

Down side is it will give a lesser gloss finish, will need an extra coat. It's also less accurate to use and get in to ridges, using the end part works for grooves and ridges.

Up side is it will take much less time, there will not be any brush marks, uses less paint.

Or use a combination of brushing and rolling, brush where the frame meets the wall and any complex ridges and roll the rest.

 

[opps]

Hi John

Unfortunately not all sanders are created equal, nor are the abrasives.

I am guessing that you are using an orbital sander. These were the de facto sanders for decorators until the random orbital sanders moved out of the spray shops into decorators merchants. These have disks that spin whilst acting like an orbital sander. They have a far higher rate of removal and thus allow you to use finer abrasives. When connected to a dust extractor they also have less of a tendency to overheat the paint.

I agree with joe that 60g sounds too harsh. It pretty much rips the surface rather than sanding it. You might find that the surface is pitted once you UC it.

With regard to burning paint off, don't do it. If the paint is sound just sand it. You will end up with a rough surface that needs filling

Under no circumstances would I use a belt sander, they can be too cumbersome to control and prone to tilting and gouging, less so if you remove the door and sand it horizontally.

 

[dcdec]

If you want a good non yellowing satin finish use the sikkens satura BL. Its similar to OB to apply, if your brush work is normally fairly good you'll find it easy enough to use.

I'm using aqua gloss more and more but when faced with flush doors the other day i bottled it and dropped back to an OB gloss. The aqua undercoat is excellent, flows out nicely but just lacks a little less covering power than OB.
The gloss i can apply brush mark free on surfaces such as architraves and skirting its just the broader areas like doors and window sills that i struggle to achieve the same finish as an oil based. The re-formulated stuff is nearly there so the next formulation will hopefully crack it, i do think its the best WB gloss currently available (that i've tried anyway).
The blue lid dulux OB seems to be ok, i've got a door at home that seems to be staying white ok or at least its a thousand times better than the crap dulux had previously launched.
Its important to use a quality synthetic brush with WB products such as purdy or picasso and you can use a drop of floetrol if you wish.

 

[ic1927]

When using water based glosses/satinwoods use a good quality synthetic brush and make sure you damp it first, this will help with eliminating brush marks.

 

[JohnDoe123]

I was using the Black and Decker Sandstorm sander... I'm using 60 because it didn't look as if 120 was taking anything off. Are you meant to notice a difference sanding for a key? Or maybe a couple of passes, even if I don't see any change with my eye, is enough as that with create enough grooves in the gloss for the paint to adhere to?

I've now ordered Zinsser BIN primer as I don't really to do much sanding on the ceiling cornice and apparently, you don't need to do much, if any, sanding at all for this primer to stick.

I also got some Purdy Monarch Elite brushes.

Now I have all the gear but no clue!

When you say damp the brush first, do you mean with water or some other liquid?

Will any old gloss roller do? Like this one? http://www.wilkinsonplus.com/wilko-...wilko-lint-free-roller-set-mini/invt/0288340/

 

[joe-90]

You don't need primer on the cornice - just emulsion.