Deck sanding advice

[Loki429]

I would like to sand my new Ironbark deck before oiling it and am seeking some advice and guidance from others that have done this before if I can please.

The timber is in good condition with no splinters or rough spots. The main reason for sanding is to bring back the full colour of the timber prior to oiling it. It has ben laid now for approx 2 months; there is approx 50 sqm of deck, plus another 10 sqm of stairs.

I would prefer to do the job myself as I have built the rest of the deck myself and am thinking of hiring a sander from the local hire shop (Kennards, Bunnings etc).

What type of sander should I be hiring? I have seen a "drum" sander for $65 per day at Bunnings.
How long do you think it would take? Will I be able to do all the sanding with a hire machine in the one day?
What grit sandpaper should I start and finish with? I've heard that going too fine will result in a slippery surface.
How much sandpaper will I consume?
Also I have a small handheld belt sander that I can use for some of the fiddly parts, and the decking is screwed down so I am tempted to unscrew planks in hard to reach areas and sand them individually if required. Is this sound thinking?

Any advice very welcome!

Cheers,
Loki

[Dr - 307]

Happy New Year Lok,
Cleaning it with deck cleaner won't help? I thought that would bring it back. That's it's purpose isn't it?
Cheers,
Doc - 307.

[Dusty]

G'day, Loki.

The stairs will want to be sanded with an orbital sander, perhaps 80 or 100 grit.

From what you've described, the main decking should really only need to be sanded with a rotary sander/polisher type machine and the edges done with the orbital. You can hire these buffing machines from the usual hire joints, but I'm not to sure about whether they carry the sandpaper you'll need to do it with. So, I'm suggesting you get onto one of the floor sanding supply mobs in your locale and get hold of some 80 to 100 grit paper suitable for a Polivac or Canterbury sander. In fact, you might be lucky enough to find a flooring supply who hires out the required machinery.

I'd avoid using a drum sander on it if you have never used one before. The results will be pretty disappointing once you start applying the finish.

[Ashwood]

A drum sander can really eat into your floor, and as Dusty said, if you're not used to it, you can create "rolling hills and valleys". A large orbital sander from Bunnings or any hire shop will do it nicely and gradually; and is really easy to use (although they are really heavy to cart from your vehicle to your deck, so get help if you're not strong).

[Loki429]

Ok I'll stay away from the drum sander then!

Re the Orbital sander - is this the type?
http://www.kennards.com.au/page.asp?37=1196&E_Page=2294
Or is this a rotary sander type?

Am I correct in understanding the orbital sander operates in the same manner (except a lot larger) as a handheld 1/3 sheet orbital sanders most of us already have in the shed? My experience with these on any timber projects in the past has been that they are very slow :(.
Is the rotary sander type a full circular motion and if so won't it be sanding across the grain a lot of the time and leaving scratches?

I had a go at sanding part of the stairs on the weekend using my belt sander (75mm wide belt). I was happy with the end result but could see it taking a long time to do the entire deck. Plus the thought of crawling around on my knees crouched over fighting a belt sander that's continually trying to run away from me for a day would kill me!

I've got this weekend to myself so I might go hire one of these sanders and give it a go! I'll stay away from the drum sander as it sounds like it is too harsh and I could do some damage to the deck.
Is it reasonable to expect to be able to sand the whole deck in one day?

Also what perparation should I do to the deck prior to oiling it (& after sanding)? Is a thorough sweep sufficient? Blow off with compressed air? Vacuum?
Or as Dr-307 says should I use one of the deck cleaner products? Perhaps a wash down with NappySan or a high pressure hose? The problem with the washing option however is that the timber then ends up wet and will need a couple of days to dry thoroughly before oiling, which then gives the dogs a couple of days to put muddy paw prints all over it again!

Oh and I have already chosen and purchased Feast & Watson oil to put on it.

Many thanks for your help. I'll take some photos before and after and post them here after the weekend.
Now all I have to do is make it through another 4 days of work in the office :(.

[oohsam]

Hmmmm....Me and you started at about the same time Loki, and my deck has faded heaps since I put the boards down. Its good, coz all the goo inside the boards has comeout and allowed the boards to really dry out properly.
Im not going to sand mine though. I was going to just deck clean it and oil/stain it....

That floor sander is really hard to use. Everything is in opposite when controlling it! Too hard!

[Loki429]

Hi oohsam

Yeah I really liked the colour of the decking when it was first laid and it was wet - had a very nice red colour to it.
Now however it has gone grey when dry, and goes quite dark when wet. I'm starting to wish I had have oiled it as I laid it! (Being Ironbark
it doesn't have the tannin bleed problem Merbau does.)

We'll see how it goes...

[Dusty]

Ok I'll stay away from the drum sander then!

Re the Orbital sander - is this the type?
http://www.kennards.com.au/page.asp?37=1196&E_Page=2294
Or is this a rotary sander type? Yep, that's the sort of thing I'm talking about. But you will still need to chase up some sandpaper to use on it. I'm recommending SIA double sided 407mm 80 grit discs. From a floor sanding supply shop.

Am I correct in understanding the orbital sander operates in the same manner (except a lot larger) as a handheld 1/3 sheet orbital sanders most of us already have in the shed? My experience with these on any timber projects in the past has been that they are very slow :(.
Is the rotary sander type a full circular motion and if so won't it be sanding across the grain a lot of the time and leaving scratches? The finishing action is very fine and should leave a pretty much scratch free job

I had a go at sanding part of the stairs on the weekend using my belt sander (75mm wide belt). I was happy with the end result but could see it taking a long time to do the entire deck. Plus the thought of crawling around on my knees crouched over fighting a belt sander that's continually trying to run away from me for a day would kill me! It would be a slow agonizing death. Give this idea the heave ho.

I've got this weekend to myself so I might go hire one of these sanders and give it a go! I'll stay away from the drum sander as it sounds like it is too harsh and I could do some damage to the deck.
Is it reasonable to expect to be able to sand the whole deck in one day? Of course, but, if you start mucking about having things like smoko breaks, lunch that sort of thing, well, who knows how long it will take.

Also what perparation should I do to the deck prior to oiling it (& after sanding)? Is a thorough sweep sufficient? Blow off with compressed air? Vacuum? Give it a decent vacuum


Oh and I have already chosen and purchased Feast & Watson oil to put on it. Cool

Many thanks for your help. I'll take some photos before and after and post them here after the weekend.
Now all I have to do is make it through another 4 days of work in the office Good luck with that. :(.

Have fun.:cool:

[Ashwood]

Hi Loki429,
Your Kennards photo is a rotary orbital sander - which has a slight rotational movement in addition to the orbital motion. Have not used one of those, although I believe it will be a slightly faster machine than a pure floor orbital one. Not sure if it could leave circular marks, so watch your sandpaper grit that you're using an appropriate one which won't leave circular marks.

The one I was referring to is a pure floor orbital sander - you are right that this has the same action as the handheld orbital ones, they basically have a small quick action which is almost like they just vibrate. These are slower than the others, but leave a very smooth fine finish and you can load up with coarser grit sandpaper. But they are a safer option than drum sanders if you're not familiar. Drum sanders are the fastest and eat away mms quickly but this can damage your floor quickly and permanently! The floor orbital sander has a rectangular base.

I'd go for the orbital one if your surface is just rough, but fairly level ie. the machine is great for smoothing but slow if you want to get the surfaces perfectly level.

If you decide on the rotational one, perhaps let the forum know your experience was.

Good luck.

[Loki429]

Looks like the gremlins got me on this one! I posted a reply here this morning but it never appeared :(.

Anyway I hired one of those floor sanders on Saturday and all went well.

I started with an 80 grit screen and found the machine quite easy to handle and use, and also that it was quite gentle on the deck. This could be because the deck is Ironbark and is very hard. On some of the stained (black marks) areas and some scratched areas I used my small belt sander first and then tidied up with the orbital floor sander.
I then went over the whole area again with a 120 grit screen. The machine was able to sand right up to the wall and around the posts, leaving me with very little to be done by hand at the end.

I was expecting it to take me and entire day +, however it only took me 4 - 5 hours in total. I then had enough time on Saturday to get one coat of oil down too!

Before oiling I used one of the garden blower/vac units to get rid of all the dust. Worked quite well and luckily the neighbours on the downwind side were out for the day! I ended up having to tape plastic over the spa too as the dust managed to make it's way under the cover and into the water. Luckily I checked, and lucky the filter was able to remove the dirt.

Overall I am very happy with the result and glad I opted to sand first instead of oiling straight off. I believe I got a much cleaner timber surface without any of the water stains and scratches that it has collected over construction and the last few weeks of use.

Here's some pics of the sander and the before/after job. I've got one coat of oil on and will do the second coat later this week (when it stops raining!)

Cheers,
Loki

[oohsam]

Loki. Im going to do EXACTLY what you did. Was the sander easy to use. I've used an orbital polisher on tiles once and it was so hard to steer/control. Put a few holes in the plaster. How much did this set u back to hire etc.

Just to get it right, You dont wash the deck after you sand right, you sand, blow the dust and then just oil right away?

[Loki429]

Hi oohsam

I found the sander easy to use. As long as I didn't try to force it to do anything and let the handle stay "loose" the sander would sit flat on the floor and do its job. As soon as I tried to force it or held the handle too high/low the sander would start to vibrate and jump all over the floor.

When its finished don't hose the deck as you'll then have to wait a day or two for it to dry, and risk getting water stains on it again. All I did was vacuum and blow with one of the garden blower/vac things. You could wipe over it with a cloth if you want, however it is an outdoor deck not an inside floor where you're after a perfect dust free finish.

As for damage with the sander - the only problem I had here was that there was a rivet sitting slightly above the rubber edge that was sharp. I put a few layers of tape over this to prevent it from scratching the posts or the brick wall as I rubbed up against them.

Seeing what you've done with the rest of your deck I don't doubt you will have the skill to give one of these sanders a go.

cheers
Loki

[oohsam]

Great info loki. Thanks I'll give it a burl and see how I go.
You're a champ.