Low E Coating

I’ve been asked to submit a bid on a commercial CCU. The building is 2 stories and a lift will be provided so it’s a pretty sweet gig.

One stick in the spokes is that on each of the 702 panes there is a sticker on the interior side (side #4) that says “Low E Coating Side”.

Low E can’t be scraped with a razor so I need to use the best solvent available for getting stickers off of Low E Coating.

One plus is that the stickers are very small. Any suggestions as to a great solvent to get these stickers off. I’ve got Oil-Flo. Is it safe on Low E coating.

Other than these small stickers the glass is in great shape. Just a lot of dust. All debris is water soluable.

Any advice appreciated.

Have the stickers been on for a long time? When I run into that I just use my regular solution. soap and water. I will wet up a few window at a time and get the stickers really wet. then I peel them off normally works pretty good. sometimes I will use a wet huck to wipe the excess sticker goo off and then wash as normal. Are these windows double pane? I have seen in some cases that the sticker says “low e this side” on the #4 side but is acutally on the #3. Not sure if oil-flow or goo- gone will harm the low e.

Although the windows are newly installed the stickers won’t peel off. They have that stubborn adhesive that is a pain to get off.

I myself question whether the #4 side is actually the Low E side. The sticker may be intended for the installer to see which side of the glass goes interior and which is exterior. Being commercial framed glass I guess it wouldn’t be too hard to get it wrong if not labled.

I’m hoping that the Low E coating is on side #3 and that the stickers can be gotten off with a metal scraper.

Try Goo Gone. It’s at Home Depot. Then remove it with Magic Eraser. I had some very stubborn adhesive tape to remove and that worked for me.

The low-e coating that I’ve dealt with will cause a drag on the mop when you run it across. That should be a good test of which side it is. All Pellas that I can recall have the low-e on side 3. Are they “Smellas”?

Low-e is not supposed to be on the outside of the unit. If it is the product is defective. I’d check w/ the contractor or window installer as to whether or not the low-e is truly exposed if it is I’d leave the sticker on the glass. If you remove the stickers the next time these windows need cleaned and have some stubborn debris on them someone is going to use a scraper and then there will be a problem.

Tony, these stickers are definitely meant to be taken off. They are right in the center area of the pane and are very opaque.

I can’t imagine why they would put stickers on Low E coating. This must just be info for the installer of the windows to indicate which side is interior and which side is exterior. The Low E coating is probably on side #3.

I’ll have to contact the manufacturer and find out for sure before I take these stickers off with a metal scraper.

Low-E is applied on either surface #2 or #3, dependent upon climate. The sticker is for the sake of the installer.

If you are really unsure, you can always measure:

Man, that’s a cool tool and just what I need to be 100% sure about this Low E. I Googled the Glass Chek + and it costs $965.28 so unfortunately that ain’t gonna happen for me.

I read somewhere on the net about a test using flame from a candle and reflections of the various panes on an IG unit. I think the relection of the Low E is supposed to be a different shade from the other 3 panes. Maybe I’ll try that if I can find the info again.

But thanks for the info Larry.

Here’s a different Low E tester for $189.00


I use the Merlin myself.


53.95 British Pounds is about $78.00 USD. They had it to me in less than a week.

I’m pretty sure the one Larry posted about will find the exact surface the low-e is on. The others only work if they can come in direct contact w/ the low-e coating. If you’re worried about it being in an exterior surface the cheaper ones will work fine.

The pic I posted was a sample of an analyzer, not a recommendation or endorsement.

So it’s not Laczko approved!

I’m not going to bother buying any of the Low E meters. The cheaper contact meter would definitely suit my purpose but I’m convinced that the Low E stickers on side 4 are there for the installers.

After consulting with experts I feel confident that the low E is on side 3 just as we all suspected.

Thanks guys for all of your input!

I use the meter referred to here for my tinting aspect of the business:

And it tells you everything… which surface and whether it is there or not. But here’s the deal:

The Low E soft coat is always done in between panes because it is subject to not only easily scratching, but also corrosion when moisture or oily hands or whatever comes in contact with it. So the only Low E coating that would be on the outside is a “Hard Coat” or if you like fancy words “Pyrolytic” coating. All that it means is that it can handle regular cleaning (no blades) and usually looks like a tinting or metallic coating on the glass. They usually put it on large plates of single paned (not IG units) architectural glass, since there is no where to put a soft coat. I would say that based on your description (especially if the contractor doesn’t know, because it would be special in the building’s specs) it would be impossible to be anything other than what Larry referred to as a helper for the glaziers who installed the glass to know which way is out (which affects the performance of the coating depending on the climate of the area).

Just my 2 cents.

The Merlin is not solely a contact meter. It works in two separate modes and will detect Low in on sides 2 or 3 of double glazed units.

So let me get this straight.

I can use a blade on the exterior panes of Low E coated glass? (as long as the glass doesn’t look tinted?)

I am sort of confused and have a Commercial CCU scheduled to begin tomorrow.

Please help.

Personal Cell # 24/7 = 405.923.2614

Get your razor out and get going with it… First few windows keep an eye on your guys and check for scratches. Grab the G.C. and tell him his windows are defective if you see start to see any scratches. Stop and shift methods and charge a whole lot more. Soaking, plastic scrapers, 0000 steel wool, magic eraser pads, throw a little baby power on your steel wool for silicon…

I rarely see Low-E on an exterior surface, but if I used a scraper on it, the issue would be with the coating and not a scratch on the glass due to fabricating debris – two different subjects/issues.

BTW, never use a plastic scraper. Debris may lodge into the (soft) plastic and travel with you to other glass surfaces, causing scratches.