Sanding away previous coating

[Richard Babley]

A couple of years ago I painted a climbing frame in the garden with an exterior coating system (Ronseal 5yr woodstain). It's now flaking so I'd like to re-paint it with a penetrative wood treatment / wood stain (for example Barrettine wood preserver). Pictures below.

Obviously I need to sand away the previous coating but I'm not sure how deeply to sand. I've lightly sanded using a fine grit (120) until the previous shine has vanished (I presume the shine is the Ronseal coating).

The wood is stained a mahogany colour, some of this colour would have been added when the frame was manufactured (the manual says a water repellent was added). There might also be some wood stain from the previous owner, I don't know what.

My sanding also took away some of this colour, revealing the bare wood in patches. When I painted a test patch with the new stain the darker colour shows through.

So - Should I sand further until the bare wood shows, removing the previous colour? I'm not worried about the aesthetics, the main thing is that the wood preserver soaks into the wood properly.

Or have I been sanding too much?

Or am I being entirely stupid and I should be doing something else?

Picture 1 - before any work, with climbing rocks removed showing original factory finish

Picture 2 - the reverse of the picture 1 after sanding. I've painted the two rungs to the left, the other rungs have not been painted. I've also painted the top left of the joining plank

 

[Droogs]

In the pic it looks like you screwed it together, if so, then I would disassemble and either run it over a planer or give it a quick going over with a #4 to clean wood and then reassemble

 

[lurker]

Being an idle bodger, I would just remove loose crud with a wire brush and slap on the preservative.

Trick with outdoor furniture is do it every year.
Little and often

 

[Richard Babley]

Thanks, I hadn't considered using a planer. So consensus is to strip away all of the existing colour?

 

[Mike Jordan]

Hello Richard
This will probably cause a bit of protest but if you think about it, external furniture is only coated to improve the appearance. The so called preservative coatings can't get to where they are really needed, in this case it's the joint between the rungs and strings of the ladder. Water will get into this joint and will in time be the area where rot starts since the water doesn't dry out and the timber preservative can't coat the surfaces involved. In the days when wooden ladders were widely used it was considered to be stupid to paint them. Varnishing will give protection against water while allowing any discolouration caused by water penetration to show up before the rot becomes terminal. In the instance of a ladder rung that's probably the correct term !
I know people who spend vast amounts of cash painting furniture and fence panels to the belief that they will last longer as a result, if it's being done for appearance that's fine but they won't last a week longer.
It's much better to spend the money on more suitable timber for the furniture in the first place. All my garden furniture is made from Iroko, yes it has been coated to keep the domestic peace, but it will last about thirty years even when totally neglected. As you can see this bench is 22 years old but still sound.

Mike.

 

[Jacob]

Being an idle bodger, I would just remove loose crud with a wire brush and slap on the preservative.

Trick with outdoor furniture is do it every year.
Little and often

Being an even idler bodger I'd remove loose crud the same and brush on raw linseed oil thinly but make sure it runs into the gaps. Only takes a few minutes, takes two days to dry, very weather resistant and organic/ non toxic.
Next year the same again
I wouldn't fancy preservatives on a climbing frame - it'd get to the climber's skin.