Sanding and Priming a Varnished Daybed to paint white

[DaleBlack]

Hi I have a wooden daybed as below. I think its from Indonesia so not sure the wood type. I believe its varnished as where I have sanded there is a white powdery substance.

I have been using 120 grit. We intend to prime it and then topcoat with a exterior water based enamel in white. Is that Heresy to a woodworking forum?

It sits outside under broad eaves but receives a fair amount of sun.

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some questions if anyone can help

Q1
I am finding the intricate parts hard to degloss, you can fold the sand paper and try to get into all the crevices but its quite hard.
Would a dremel with accessory like this

412531

https://dremel.com.au/en-au/Accessories/Pages/ProductDetail.aspx?pid=512E

or this

412532

https://dremel.com.au/en-au/Accessories/Pages/ProductDetail.aspx?pid=EZ473SA

the problem is i might start sanding the detail away.

Or just stick to sanding?

Q2
Post sanding I will vacuum down the works. But I would like to wipe it down with a moist cloth, if the primer coat is oil based would mineral turps be okay and water if I use a water based primer? but i dont want to affect the varnish somehow or cause the wood fibres to rise.

Q3
What is a suitable primer baring in mind the odd spot where deglossing hasnt properly occured?

I have come up with these 3. Is oil based still superior?

Zinsser Coverstain (oil based)
Dulux Prepcoat 1Step Oil Based Primer, Sealer & Undercoat (this was Dulux technical help line advice) - they recommended this over their Dulux Precision Range Max Adhesion primer which is their range to combat Zinsser.

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SOLVER LINE 4311 - MAXI PSU - water based


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Q4
Topcoat
Dulux Aquaenamel water based so it doesnt yellow, maybe semi gloss.

Cheers

[tonzeyd]

Hi,

Am most a DIY'er but have tackled my fair share of furniture restorations so take my advice with a grain of salt

Q1: No need to get it down to bare timber, hand sanding will be suffice. The idea behind sanding is to scuff the surface to give the primer something to cling onto rather than a sleek oil finish.

Q2: Easiest way to do this if you have a compressor is to blow all the dust away and go to bunnings and grab yourself some tack cloth (they're about $3 each) and rub away any remaining dust adhering to the surface.

Q3: Either will do fine, I personally prefer the Dulux single step as its easy to clean up afterwards

Q4: I've used both water and oil based enamels and must say if you can avoid it use an oil base. Dulux does produce a UV stabilised oil based paint which costs slightly more than their aqua enamel which the local paint shop assures me being UV stabilised won't yellow. The Aqua enamel is quite difficult to get a smooth finish on, the only reason why we ended up using it was due to the smell it caused inside the house and with Pets that are sensitive to strong smells it isn't ideal. But if you're painting outside it shouldn't be a problem.

[DaleBlack]

Hi thanks for the quick response Tonzeyd


Q1: No need to get it down to bare timber, hand sanding will be suffice. The idea behind sanding is to scuff the surface to give the primer something to cling onto rather than a sleek oil finish


Can I ask specifically with the Dremel, will it make the laborious hand sanding faster on the intricate parts? or do you see those attachments i linked being too rough and I will end up sanding out (reshaping) the detail.
Do you have any other tool or ideas on making it less laborious?



Q3: Either will do fine, I personally prefer the Dulux single step as its easy to clean up afterwards



As i listed 3 primers, two Zinsser and Dulux were oil based and Solver was water based. As you mentioned 'its easy to clean up afterwards' in relation to Dulux did you in fact mean this

https://www.dulux.com.au/products/63089139 (https://www.dulux.com.au/products/63089139)

[DaleBlack]

Also meant to add, can you link the oil based but non yellowing Aquaenamel Dulux product?

They have a oil based range as below

https://www.dulux.com.au/products/378

I just check with them and they said it still will yellow.

[tonzeyd]

Unless you're very good with dremel, I'd say you'll end up causing more harm than good. Plus you'll end up creating small divots in the detailed bits. Just scuff it up with some sand paper, as said earlier no need to remove everything. All you're trying to do is make sure the primer adheres to the surface rather than removing all traces of the previous finish. Shouldn't take too long by hand.If you really must attach it with a dremel I'd recommend using the diamond burrs.

Or if you have a sand blaster that'll make quick work of the intricate stuff but if you''ll need to be fairly careful with it.

Yep thats the Dulux primer I was referring to, its suitable for both water and oil based top coats.

Can't recall the product name exactly, as i haven't used it before. It was a product recommended to me by Inspirations Paint, If you contact them and ask for a UV stablised oil based paint they should know what you're talking about.

[david.elliott]

+1 for the zinsser, used it on laquered Ikea shelves after a light scuff up with sandpaper/maroon scotchbrite.
Works well, and washes up with water...

[Arron]

Another alternative is to use this
The Flood Company Australia » Paint Additives » ESP (http://www.floodaustralia.net/products/paint_additives/ESP.php)
And do no prep at all!

It does work . I've used it over varnish extensively.

Cheers
Arron

[DaleBlack]

Another alternative is to use this
The Flood Company Australia » Paint Additives » ESP (http://www.floodaustralia.net/products/paint_additives/ESP.php)
And do no prep at all!

It does work . I've used it over varnish extensively.

Cheers
Arron
Hi Arron I have seen that product and was skeptical. If i combine it with the type of scuff up you can already see, I should put myself in a good position for Zinsser over the top?

[Arron]

Hi Arron I have seen that product and was skeptical. If i combine it with the type of scuff up you can already see, I should put myself in a good position for Zinsser over the top?

I've found that if it's a Flood product then it will work - and no, I have no connection with the company.

I've used the product back to about 2004 and not had a problem with it. More recently, in 2013 I had a whole house full of varnished woodwork that I wanted to repaint and used ESP. That's not a long time I guess but it's still good, and that place is a rental so gets a hammering. So I think you will be ok with it - but it's always wise to do a test. Put some on, then overcoat with your chosen finish, then leave two weeks which is enough time for all/any catalytic reactions to occur. If you can't scrape the paint off with a fingernail then you are good to go.

Personally, I think you are all right to simply use the ESP, then undercoat, then topcoat - so no sanding or esoteric primers required because that's pretty much what the product does - keys into the surface. That's what I would do if it were mine but no-one is really going to guarantee you because no-one wants to be responsible for any unforeseen circumstances, especially with Asian-sourced furniture that has been coated with god knows what.

[Xanthorrhoeas]

That style of furniture is often described as being made of teak if it is designed for outdoor use. If it was meant to be indoor only then, as above, who knows what Asian rainforest timber it is. I concur with tonzeyd's advice above and would avoid the Dremel and simply scuff the surface.

Although water-based paints are easy to clean up they work primarily by producing a 'plastic' skin on the surface of the wood. If it is out in the weather and gets very wet that can be a problem as any water that does get in - through a scratch, a crack at a joint or missed spot, is trapped inside the skin and the timber stays wet for a long time. That quickly leads to rot. Oil-based primers and enamels do not seem to suffer from the same problem so are recommended for timber out in the weather.

Like Arron I have found the Flood products to be very good, though my experience is with their marine oil Deks Olje (The external oils work by saturating the timber, which I have found to be excellent for preserving the wood but is not the finish you are looking for). Any good brand of oil-based primers and paints (e.g. Dulux) should be fine.

[DaleBlack]

Hi guys, thanks for the replies.

I have almost scuffed (no dremel :>) the entire piece with 120 grit.

I will vacuum the dust off with a bristle tipped std vacuum. I dont have a compressor at present to blow it off.

Prior to the next coat whether Flood or straight to Zinsser Coverstain - what in addition to vacuuming can i do to ensure all the dust is off?

Given you clean oil based paint up in mineral turps, i was going to lightly moisten a cloth with turps and wipe it, constantly changing to a fresh section.

Is this fine? it wont react with the scuffed varnish? - i assume if i used Isopropyl Alcohol or Painter Thinners then it would negatively affect the varnish and negatively affect my primer coat.

Thanks

[DaleBlack]

Although water-based paints are easy to clean up they work primarily by producing a 'plastic' skin on the surface of the wood. If it is out in the weather and gets very wet that can be a problem as any water that does get in - through a scratch, a crack at a joint or missed spot, is trapped inside the skin and the timber stays wet for a long time. That quickly leads to rot. Oil-based primers and enamels do not seem to suffer from the same problem so are recommended for timber out in the weather.

.

I will use oil based for the primer, but due to yellowing i was going to use water based dulux aquaenamel for the 2 x topcoats. Are you saying this is okay or that I should be oil based for the primer and topcoats?

[Arron]

I don't think oil based enamels yellowing is really a big deal. Have a look at the woodwork on the houses in your street - they look white, not yellow. It's also common to put a little touch of blue (outdoors) or black (indoors) in the white to make it cover better and disguise any colour shifts. A really experienced paint salesperson will know how to do 'a dab of black' for you.

For cleaning up dust, I usually have a compressor handy so blow the dust off. You can use tack cloths too. You can buy these, or make your own. I think you make them by soaking a rag very lightly in thinned varnish. - but google will confirm.

Really though, the compressed air is best as it gets right into the corners where even a brush won't reach.

[Arron]

Forgot to add.

I would also check whether it's teak or not before painiting it. Teak has a distinctive smell, a heady spice smell like nutmeg and cinnamon combined. Sand some bare wood, then sniff it. If it's teak it's worth a whole lot more then if it's just some local Asian timber. Teak isn't usually painted because it's one of the few woods that doesn't need it.

I bought a chair in the same style home once - picked up from the council cleanup. The owner told me it was Balinese. I was thinking it was teak but when I tested it, it wasn't.

[rob streeper]

For a really smooth finish use sprayed white lacquer primer. Sand off the tooth of the primer with 3XX-4XX WD sandpaper. Do the details with a sanding stick, not a powered device. Wipe thoroughly with a tack-cloth dampened (damp not wet) with mineral spirit and allow to dry for a couple of days. Then spray a high-solids waterbase finish such as outdoor enamel house-paint diluted (per mfr. directions) with Floetrol and water if your mfr. allows. Two coats carefully applied should be glassy smooth. If you want to go with oil-base as above but substitute Penetrol for better flow-out.

Here's a couple of local brands: https://www.ppgpaints.com/products/speedline-white-lacquer-undercoat, SHER-WOOD® CAB-Acrylic Lacquer White | Wood Finishes


(http://oem.sherwin-williams.com/products/wood/pigmented-wood-finishes/solvent/non-catalyzed/sher-wood-cab-acrylic-lacquer-white/)