UV Protection

lithgowlights

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As many of you know I started adding a number of 3D printed items to this years display, but plastic in the hot Australian sun is far from ideal in terms of lifespan, so I did a few experiments this year to determine a way to protect the investment and I have come up with an ideal solution based in tests here

What I did was get a tint tube kindly donated by BensChristmasLights and masked it off into 6 sections, and spraypainted each section with a single or combination of 2 clear coats, and the results were pretty obviously grouped into 2 groups - did not work, and worked. My best options, and the one I am using this year is below. These were sat outside since March this year, and while that did include winter, they were positioned so they were in the sun as much as possible until late October.

Ideal - Primer coat of Dulux clear Plastic Primer (Sold by Bunnings), and then a top coat of Septone Acrylic topcoat clear (Available here from Supercheap Auto).

Pretty darn good runner up was just the Septone spray, but it did peal a little bit as it did not appear to have bonded real well to the base plastic. If you have things that don't get bumped and rubbed then this might save you a few dollars, but I do suggest using the Primer.

OK - A runner up that was pretty good, but not as good as the solutions above was simply a coat of Supercheap Auto Acrylic Clear.

Useless were Dulux Duramax Clear Gloss and White Knight Clear Gloss as they appeared to have no UV protection at all.

I also repeated the same test on some of the LED covers donated by AussiePhil and while they were not out as long, there was a clear difference when using the Septone paint - they were both not yellow AND not brittle, unlike the other ones with the other paints. The supercheap auto acrylic clear was pretty good as well but only when used with the Dulux primer - it flaked off without it.

All my LED covers were given the primer and 2 coats of Septone clear, so I guess I'll see how they look in January, but I think they will last OK. The sprays also have the advantage of waterproofing the covers, as they are not that waterproof without some treatment, and the untreated ones did let water in during heavy rain events - just a few drops, but it was noticeable

One last tip - be careful of the Dulux Plastic Primer if you have araldite on your items - it causes araldite to turn rather yellow, as I found out with the 12 pointed Pixel stars...
 

AAH

I love blinky lights :)
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Any chance of some pics Dave and maybe in table form?
 

lithgowlights

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Yep I'll post Pics tomorrow for the tint tube, but the LED covers were tested to destruction (I wanted to see if they went brittle) so no longer exist. The LED covers and tint tube are here in a chart with ratings, so no problem there
 

i13

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Thank you soooooo much. I'll spray my first pixel nodes this year because those of you who've chatted with me enough will know that lights yellowing in any way shape or form is one of my pet hates. I DON'T want to replace the pixels after what it took to get them set up. Are the pixels glued with Araldite?

Are these the products you used?
http://www.bunnings.com.au/dulux-duramax-325g-plastic-primer-spray-paint_p1400720
http://www.supercheapauto.com.au/online-store/products/Septone-Aerosol-Paint-Acrylic-Clear-Topcoat-400g.aspx?pid=33194#Recommendations

Looking forward to seeing the pictures.
 

lithgowlights

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They are the 2 items, yes. I have also sprayed a few new pixels and the epoxy they use does not appear to yellow like the Araldite I used, so you should be safe. It's only the surface that yellows, not the rest, so I probably plan on spraying nodes as they are added for the hell of it - at least those that wont move as they are on frames
 

i13

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How many layers of primer and topcoat did you use?

I have bought the Septone topcoat but Bunnings was out of stock of the primer so I'll try again soon.
 

lithgowlights

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1 primer and 2 topcoat here. The primer was a reasonable coat, but the topcoats were not too heavy to avoid runs
 

AAH

I love blinky lights :)
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Is it tomorrow yet?

lithgowlights said:
Yep I'll post Pics tomorrow for the tint tube, but the LED covers were tested to destruction (I wanted to see if they went brittle) so no longer exist. The LED covers and tint tube are here in a chart with ratings, so no problem there
 

lithgowlights

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A = Dulux Plastic Primer + Dulux Duramax Clear Gloss.

B = Dulux Plastic Primer + Septone Acrylic Topcoat Clear. This is actually really dirty in the pic as I have tried rubbing it with a dirt-covered rag to test its hardness and see if it will peel off - it did not, and was marginally the best overall, even though it looks barely OK

C = Dulux Plastic Primer + White Knight Clear Gloss.

D = Septone Acrylic Topcoat Clear. Worked well, but poor bonding to the plastic when no undercoat was used, and it actually pealed off in sections

E = Supercheap Auto Acrylic Clear. Worked well, but again poor adhesion. I tried this with the undercoat on a separate piece of pipe and it bonded well, but still peeled off the topcoat, and can be scratched easily. Probably the best in terms of protection, but did not seem to want to bond to anything well enough to justify its use, but I did think later of using it as a topcoat over B above and see if it works

the stripe below E was an area covered in tape as a test. Even the painted sections were slightly yellowed compared to it, but I put that down to the fact that there was no top on the pole for the last month or so, and the interior has likely started to weather as well.

F - Dulux Duramax Clear Gloss
 

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i13

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I have just finished spraying hundreds of new pixel nodes. They'll be on a north facing A frame when I get them up so this'll be a thorough test of the sprays. I'll post the results when I take them down in early January. Thinking I'll put a non-sprayed node up there too for the sake of comparison.

Thanks again for posting about your UV protection.
 

i13

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I've been meaning to post here for months. Unfortunately this didn't work. The spray stayed sticky and didn't stop the pixels from discolouring. Fortunately it has set properly on the part of the pixels that actually emits the light.
 

bpratt

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I saw a post recently of some aerosol pack stuff to use on leaping arches to prevent or at least reduce the effect of UV on them.... can't remember where it was now, other than I think it was available on Amazon.
 
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