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Old 09-09-2017, 11:00 AM
TASEsq TASEsq is offline
Join Date: Aug 2017
Location: Melbourne, Australia
Posts: 95

One further query re those who have used the Wattyl Super etch and/or the Protec - does this stand up to dumpling after priming?

It seemed to me that I probably would find it easier to dimple after priming if I were to go the pre-kote method of scuffing and cleaning.

However, if you don't have to scuff etc as it is "self etching" then I guess I can dimple before priming?

Originally Posted by tgmillso View Post
Not sure where you are in Australia, but I've used Stuart Systems Ekopoxy and have had good results.
Tom - did you buy this out of the US? Or from Skyshop?

Last edited by TASEsq : 09-09-2017 at 11:19 AM.
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Old 09-09-2017, 02:47 PM
salto salto is offline
Join Date: Apr 2015
Location: Wee Waa Australia
Posts: 257

I've been using the Wattle product and scuff the dimple lines prior to dimpling then scuff the lot prior to painting. Where I've missed the odd dimple it seems to stand up to dimpling after but not my preferred method. The self etching properties, quick drying, availability and ease of use make it an attractive product.
Kit 140241
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wings almost complete.
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Old 09-09-2017, 05:17 PM
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Bootscooter Bootscooter is offline
Join Date: Jun 2011
Location: Sydney, Australia
Posts: 45

I have recently primed my RV14, and got great results, would certainly do it this way again.

I bought the same stuff Boeing use on their jets (light green colour) BMS10-11 from PPG in Victoria.

Then Alumiprep, Alodine, Prime. And as Vans say the Aeroplane will be good for the grandkids.

The Alumiprep and Alodine is done using baths, so eliminates the mechanical etching with scotchbrite.

The BMS10-11 is very tough, and easy to apply, however all the safety precautions need to be taken as what's good for aeroplanes is not good for humans.

Rgs Chad
Chad Boot
RV14 140331 VH-VNX. Flying
RV10 Standard Fuselage Complete
RV10 Empennage complete
RV-7 Slider Flying VH-VNZ
Sports Aircraft Assn Australia. Tech Councillor.

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Old 09-09-2017, 05:17 PM
tgmillso tgmillso is offline
Join Date: Nov 2012
Location: Launceston, Tasmania, Australia
Posts: 585

I too have found that the superetch holds up perfectly well to dimpling, better in fact than the Stewart Systems does. I generally like to give it overnight at least to fully cure before I dimple.
If you are doing large batch numbers and are close to other houses/people, then Stewart Systems is your best option. For small batches (small bits of angle, etc) the Wattyl rattle can should be fine, as there's not nearly as much mist/overspray with the rattle can.
Regarding the mixing of any paint, I have given up mechanically mixing it (i.e. I do not use a stirring stick/mechanical stirrer any more). This came about because I thought I had a contamination issue from my stirrer, so instead I shook the paint tin instead, thinking that I would have all kinds of secondary issues from air bubbles. There was absolutely no problem, so can shaking is now my default mixing method. The only problem with the Ekopoxy is that it does settle to the extent where is can be very hard to shake, so if you don't shake it now and again whether you are using it or not, it will settle to the point that you will need a mechanical stirrer. I have also found that once Ekopoxy has passed it's shelf life it may still not mix properly. I had a batch of Part A that was 18 months old that just wouldn't mix, so I had to ditch it. I have not had this issue with etch primers, and have used ones more than 10 years old. If you are shooting Ekopoxy, then I have found that you can successfully shoot it with a touchup gun, so long as you increase the thinner rate (distilled water) by about 50%. This will let you use a smaller 0.8mm gun (rather than the specified 1.3mm gun) which will make priming smaller components far easier with less overspray. The same can apply to etch primers. I generally run 40% thinner in the Superetch rather than 30% specified max and this lets me shoot it through the smaller gun. Finally, cooling and trapping moisture out of your water is key, or you will get fish-eyes in your primer (sometimes confused for silicone contamination). Air will come out of the compressor hot, carrying moisture in vapor form. In vapor form, it will pass through water traps. It needs to condense, kind of like happens when air passes over a mountain, cools and then rains. If this air has not condensed, the water traps can not capture it. I had been chasing what I thought was a silicone contamination problem for ages, but it turns out that the moisture would pass straight through the trap at my compressor, and even the trap just before the gun was inadequate to prevent fisheyes. The solution was running the air through 8ft of copper pipe in a 200L drum filled with cold water, then into a good quality water trap. The air then warms back to room temperature in your air line at which point it is super dry as it has dumped all its moisture. It is amazingly effective, and I wish I had created this cooling/drying system at the start. On one day large day of painting recently (I am currently painting the exterior), I had been running the compressor all day, and it heated up the water to the point where I was getting fisheyes again, so I tipped the drum of water out and re-filled it with cold river water and bingo, all the fisheyes were gone. I think If I were to do it again, I would increase the copper pipe length (perhaps double) in the drum so the water doesn't have to be as cold to force the moisture out of vapor form.
For the fiberglass components I have found the Wattyl UC230 high build primer a good solution in Aus. I generally lay down a couple of medium coats or more (you are sanding the majority of it off once cured). You will have pin-holes to fill, so I generally put my leftover UC230 in the freezer to stop it curing, then go back and fill those pin holes about two hours after I have laid the UC230 down. The filling is just done with a popsicle stick , working it into each pin hole, but lightly enough so that you don't damage the soft UC230 you have laid down as it will not yet be fully cured. This will enable you to have a chemical bond between the pinhole filling the the primary coat, rather than leaving the pin hole filling to the next day when you will miss the opportunity to have a chemical bond. It will look ugly as ---- afterwards, but this will sand off, and the UC230 sands super well. I generally allow 2 days curing in Tassie before sanding, but if you are in a warmer climate 1 day may be ok. The Superetch can be applied over UC230, but UC230 can not be applied over superetch as it will dissolve it.
I hope this helps.
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Old 09-09-2017, 05:17 PM
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Aiki_Aviator Aiki_Aviator is offline
Join Date: Jan 2010
Location: Melbourne, Australia
Posts: 232
Default My approach in Oz


My approach in Oz inner suburbia was as follows:

Basically, the primer is tough. Comment was not as good as chromates.... how?

Plane will only last 200 years not 250-300.......

Oh, ok.

Andrew Long
RV10: Happy little Vegemite :-)
Feb 2015: Now fully functional..... and quick
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Old 09-09-2017, 07:38 PM
TASEsq TASEsq is offline
Join Date: Aug 2017
Location: Melbourne, Australia
Posts: 95

Thanks for the replies. Sorry for so many questions!

@andrew - what is the difference between the EAP-9/12 and the alumiprep? Does the EAP-9/12 not etch the surface to paint? I watched their video and it seems a very long winded process (induction time, spraying, dabbing off excess etc). How did you get around the mixing when doing small parts (the activator is in a pretty small bottle and seems hard to weight out accurately).

@tom that's very interesting re your water bath. Was your compressor working hard during your spraying? The compressor I've got has never had an issue with water vapour when I've painted other things (models, kitchen cupboards!). But then it only ran around every 3-4 mins maybe for 30 seconds to bring the pressure back up? Good idea though to run time metal lines with a drain at a low point in the shop. Setting up the permanent air lines is on my list.

Do you guys find you had much contamination of oil since you were using air tools and a sprayer on the same compressor? Or did you run a seperate line from the compressor for painting? (I was thinking of a split right out of the compressor - one way into the walls for the shop air (tools) and the other off the compressor for painting only).

Thanks again. This really is invaluable - the choice of primer is a hard one being here in Aus - if only we could just order from spruce and 3 days later it was here.

Last edited by TASEsq : 09-09-2017 at 07:40 PM.
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Old 09-09-2017, 11:02 PM
tgmillso tgmillso is offline
Join Date: Nov 2012
Location: Launceston, Tasmania, Australia
Posts: 585

Regarding your earlier post, I brought my paint in directly from the US when I shipped my kit over, but I understand it can be shipped air as it is not classified as hazmat. That said, I imagine air shipping is not cheap, so it may pay to get it locally. As I said before, it has a shelf life, so only get what you need (1 gal did virtually all my airframe interior priming).
With respect to the cooling drum, a picture may be found below. My compressor is a twin cylinder 2.2hp unit (9 amp at 240V), and it's enough to run my 1.3mm SprayIt 33500 LVLP gun, but the compressor is working the majority of the time. If you are doing all the prep work (including blowing down with air) priming and finally top coat in the same day, you are dumping a lot of heat into this water. Things wouldn't be so bad if I had metal pipes in my hangar, however my hangar is only borrowed temporarily, so my air lines are just synthetic rubber, which don't dissipate heat nearly as well as the metal lines, so the moisture stays in vapor form. The beauty about filling cooling tank with river water is that it's straight off the mountains so it is super cold and forces all the moisture from vapor to liquid form allowing the water trap to do it's job because I am cooling BELOW ambient temperatures. On a big spray day now, I will just leave the tap slowly running replacing the water in the drum as I go.
Regarding the spray gun I have been using, I'm really stoked with how they have been working. I purchased the two gun kit from amazon, and they really do work well at the lower operating pressures. I was told by professional painters here that there would be no way I could paint with such a small compressor, however it has been fine with these guns.
I have been using the 600ml collapsible paint cup system from GPI which is almost identical to the 3M PPS system. If you are painting etch, you can just leave the unused portion in the cup and cap it, then just wash the gun out. For the internal priming it is not so necessary, but for the external application, it is key. It saves a whole lot of cleaning up and I suspect has paid for itself in saved thinners. It makes shooting the belly of the aircraft a breeze. Also, be sure to get yourself a 360 degree swivel air fitting so you can keep the hose out of the way. Whilst your at it, you should probably get yourself a US mail box. A couple of us down here use It cost $7/mo by you will save yourself a boatload in shipping costs (I get my Spruce orders sent there and consolidate them with other items I am shipping), plus it lets you get items from Amazon that you couldn't normally access in Aus. Never get things shipped anything faster than the most economical speed, as there's always some more parts to edge finish in the meantime.
If priming really is a big deal because you live the city, then I would strongly consider not priming. Often when I speak with builders, the one thing many of them say is that they would not prime everything if they were to do things over again. It's a huge time commitment. If I lived in the city, I would strongly consider just fay sealing/wet riveting my components. I fay sealed all the lower skins in the fuselage (up to the longeron) with Sikaflex Pro as it has a super long working time. The vast majority of corrosion I have witnessed on aircraft is between faying surfaces, and thus I think if I was to do things again, I'd just run a bead of sealant and wet rivet all the joints. I used a polyurethane, which is pretty toxic, but I am trying to find a modified silicone (MS) sealant that has a long working time as a substitute in the future (perhaps for the next project...). The MS sealants are paintable (unlike silicone, which you want to steer clear of except for the high temperature application on the firewall) and their vapor is way less toxic than traditional polyurethane sealants. You would then have to only prime the angle components (the non alclad parts) which you can do with the Superetch cans. The downside of the wet riveting is it is more difficult, and once you get started, you've got to keep going, so you really need to plan well. I find the 100% cleco, semi cure, then rivet technique that many use on the tanks doesn't seem to work so well elsewhere, as it still leaves quite a bit of sealant in the joint compared to riveting. Also, get yourself a small chest freezer in your shop, or somewhere you can keep these sealants. Once you have used them , plug the ends and throw them straight in the freezer. A builder here told me that they can get up to two weeks use out of a sikaflex pro tube before it starts curing in the tube. I put my in the freezer after every use, and got more than 6 months, as these are moisture curing and if the moisture is frozen, then no reaction occurs. Anyway, just food for thought.
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Old 09-10-2017, 12:58 AM
dmn056 dmn056 is offline
Join Date: Aug 2014
Location: Sydney, Australia
Posts: 8

I spent a fair while deciding what to use. Eventually went with:

1. PreKote - apply with maroon Scotch-Brite, rinse off with water, apply PreKote again, rinse off again, check that water sheets off (if not, another PreKote cycle)

2. Akzo Nobel 10P4-3NF epoxy primer, applied with a LVLP spray gun and 1.3 tip. Part A settles in the tin, and needs a lot of mixing. It turned out to be almost idiot proof, and even areas that look terrible during application mostly dry to a good coating. It seems pretty durable, since I've been dimpling after priming without causing problems. I got the 10P4-3NF primer from Seairland in Brisbane, and they shipped it to their Sydney agent for pickup. The contact there was Glen McKenzie ( It wasn't cheap, but nor were any of the other primers I looked at.

I've also used Tempo etch primer on a couple of fiddly bits. It works well, but is very slow to cure.

Hope this helps
Dan Newman
RV-8 empennage complete
wings in progress
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Old 09-10-2017, 02:52 PM
Joeyo68 Joeyo68 is offline
Join Date: May 2015
Location: Frankston, Victoria, Australia
Posts: 80
Default System I am using in Melbourne

Hi Trent,
I am using the PPG system without alodining.

I clean with acetone, scuff with maroon scothbrite, then clean with acetone again. I apply EAP9 by wiping on with cheesecloth. When this dries, I shoot CA7700 primer, single light coat.
This process has delivered a tough coating that adheres well to the aluminium.

If you are in Melbourne, feel free to drop around to see the result.


Flying friends RV7A
Built RV7 empennage.
Building wings done - minus glass and lights.
Building Fuselage
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Old 09-10-2017, 07:07 PM
TASEsq TASEsq is offline
Join Date: Aug 2017
Location: Melbourne, Australia
Posts: 95

Originally Posted by Joeyo68 View Post
I apply EAP9 by wiping on with cheesecloth. When this dries, I shoot CA7700 primer, single light coat.
Hi Joe,

Thanks for the reply. So you don't have to apply the eap as per the instructions? (In their video they spray it and then dab the runs off which seems quite labourious). How do you find the induction time? (1.5 hours!). I suppose you can just mix the paint then start cleaning your parts (and hope you don't need a tiny bit more at the end). Also how is the try time? The TDS says 6 hours to dry -
I not other builders using the azko and it dries in 5 mins.

Where do you get your ppg from? (Just a local car place?)
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