Envirotex Help Thread

[m-Kresol]

With all the questions about how to do Envirotex (henceforth abbreviated: ET) right, I thought we could probably just write our own experiences down to extract the ultimate formula to help us and future generations

First off, I need to give big thanks to Juansolo and Cleggy, who did an amazing ET tutorial, which can be found here. The first time, I did everything following their instructions and it turned out really good for a first attempt.

After some more recent trials, I found the following aspects to be very important/noteworthy.

* One of the most important things is of course measuring and mixing. As I have access to plenty of syringes, I use 5ml ones to dose the epoxy prepolymer and the amine hardener. Use seperate syringes to dose them, as you don't want to have one of the components in the other storage container. Syringes are readily available at pharmacies and should be very cheap.

* The mixing can be done by hand, which is tedious. Again, I have access to a magnetic stirrer in the lab, which gives me about 15 seconds of stirring for a well mixed, ready to pour mixture. In the DIY spirit, a friend of mine build a simple version of a magnetic stirrer when he was 15. I found this tutorial which is basically the same thing. Might be worth doing, if you do lots of ET and or just for the fun.

* Preheating the components is also key to a good result as it makes it way easier to mix the components and to spread it on the enclosure. On the down side, heating the hardener (the bottle with the black cap) leads to a yellowish colouring of the compound. Chemically speaking, this is totally normal, as the hardener is an amine which gets oxidised under air when heated. Until now, my coatings came out crystal clear nevertheless, but the hardener only has a light yellow touch by now and is "thinned" by mixing with the second part. I still stopped heating the hardener to prevent further oxidation, just to be safe. Also, storing it in the dark will minimise the oxidation process. (sorry for the chemical excourse)

* Getting the coating bubble free is the hardest of all parts. Bursting all the bubbles will require tedious observation of the enclosure (every 10 min or so) as the bubbles form over time. Once the resin hardens, you can't remove them anymore (or fill them with more ET without seeing it). To pop the bubbles you can either exhale on them or use a blow torch/brulée burner as stated in the instructions. Both methods work pretty fine, but won't help once the ET is on the more viscous side. Warming the whole thing again with a heat gun/hair dryer only works in the first phase of drying; at some point the whole thing won't flow any more.

* Mixing the ET under vacuum conditions to prevent air getting trapped while stirring does not lead to fewer bubbles

* I just lately found that curing ET in an oven at 70 °C takes about 1-2 hours to harden it sufficiently that there will be no more bubbles forming afterwards (you can't make a dent with your finger afterwards, but it still feels a little soft). The two coatings I did that way turned out bubble free, even in thickness and glass clear! I guess, existing bubbles burst because of the low viscosity at elevated temperatures which also allows the ET to fill the left holes. Maybe (but just maybe), it also degases earlier since gas storage capacity of liquids decreases with increasing temperature, thus degassing in an early curing stage. Science for the win, bitches!

* A 1590B enclosure takes about 5 ml of ET (2.5 ml of each component) to cover it. Thicker coatings will obviously need more. There is a tool to calculate the needed amount on the suppliers homepage.


Please add your experiences, tipps and tricks! ET gives every enclosure the extra sparcle it deserves, but it is tricky to get it just the way you want it. Again: thumbs up for juansolo and cleggy's tutorial.

[juansolo]

We've been doing it a few years now and we still sometimes get shitty pours with flow marks and bubbles. However more often than not lately they've been really good.

We only heat the compounds by putting the bottles in hot dish water for 5-10 mins. It's nothing excessive.

Prior to drilling, one of the most useful things we've found lately is to coat them with Rain-X beforehand. It's a compound used on windscreens and motorbike helmet visors. It essentially fills in the tiny pits and holes so water just flows off. In this case it stops them filling up with ET dust when drilling, which really used to highlight the microscopic holes in there.

It's still hard to do perfectly. But we've yet to find a better alternative for coating pedals that's as durable, looks as good and as suited to ultra low numbers of pedals.

[bschobs]

Ancient thread here, I know.  Just did my first envirotex and I'm sure I'll have some corrections needed on the bottom edge of the enclosure. Followed Creggys tutorial.

Can anyone comment on sanding Envirotex?

Muchos gracias

[Stomptown]

I've sanded envirotex and the finish went from glossy and transparent to very dull and translucent (Practically opaque).  I'm pretty sure you could bring back a glossy finish by wet sanding and buffing but I don't think hand buffing would be the way to go. I typically use bare enclosures so when I mess up I just warm the top of the enclosure with my heat gun and peel the epoxy off.  It comes off very easily.   Not a great idea for painted enclosures though.

If your trying to sand off envirotex that ran down the side of the enclosure,  it is possible, however it takes aome effort to sand through the epoxy and you would likely sand off a bit of paint/powder coat during the process. 

[jimilee]

I use an ex's to do cut off the run down. It peels pretty easily. If the enclosure is painted, the paint will come with it though.


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[matmosphere]

I used to tape up the sides and bring the tape up a little to make a well for the ET it worked pretty well as long as you don't poor to heavily.

[bschobs]

I definitely poured too heavily... basically the sides are covered and the drips are down all the way at the bottom edge of the enclosure.  I did this before I saw the suggestion of 5ml for a 1590b so...

It potentially looks great though if I can clean up the bottom edges.  Probably ok to wet sand down there?

Thanks for the help!


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[Stomptown]

Wet sanding may take some time depending in thickness of the ET you are removing.  It will also give the paint a matte finish so you will have to wet sand all 4 sides to get a uniform look. 

Next time you do a pour, I would try pouring significantly less than you think you need and using a stirring stick (see photo below) to tease the epoxy to the edges of the enclosure.  Once the epoxy spreads itself evenly you may notice depressions where you drilled your holes for controls and switches.  If so, you can dip the stirring stick in the excess epoxy and add drops directly over the foot switch hole until you have a completely even surface.  If you accidentally over-pour the epoxy, you can dip the stirring stick into the pour above the foot switch hole to remove epoxy.  Then, wipe off stirring stick with paper towel and repeat until you see a slight depression over the drill holes.  Finally, add a couple fresh drops until surface is even again. I almost never get runs using this method.




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[bschobs]

Great advice thank you. I have another I am going to attempt this weekend!


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[jimilee]

When I pour, I do a thin line right down the middle and then spread it with a tongue depressor looking thing I got a bag of from hobby lobby. If it looks like it isn't enough, it is.


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[Stomptown]

If it looks like it isn't enough, it is.

Exactly!


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