Does Anything Bond Vinyl to Vinyl?

Which idiot did you talk to at 3M that does not know their own product line????

They make a loads of adhesives that bond vinyl.

here is a common one used by the auto upholstery guys.

3M # 80 Vinyl and Rubber spray on adhesive

What kind of vinyl? If you're dealing with upholstery, tcm has mentioned 3M. Also, some of the repair kits 'as advertised on TV' work pretty well. But again, what kind of vinyl, where, etc?

Then how about mechanical fasteners? Staple gun, nails, screws?

Or how about duct tape?

There's vinyl and then there's vinyl.

I've used MEK many times. It melts PVC pipe, flexible vinyl and most other "vinyl" stuff.

What exactly are you trying to do?

If you are looking for a contact adhesive 3M 1300 is a great choice.

3M™ Scotch-Weld™ Neoprene High Performance Rubber ... Not an endorsement, but it's really good!

APPLICATION: attaching 1.5" square vinyl "patch" onto vinyl window flashing...both materials described (by their manufacturer's reps) as being "virgin vinyl" and NOT cellular vinyl.

USE: The 1.5" patches have a T-nut stuck through from the backside (and tabs folded over), so that a 10/32 screw can be used to attach solar screen (< 2 lbs) over windows. Four such attachment points around each window: two at top, two at bottom.

PROBLEMS: weight loading isn't too much (~1/2 lb each patch), but thermal expansion loading (vinyl expands / contracts like CRAZY) can be problematic, and summers are HOT here (> 110ºF).

I'm still going with either straight MEK (or acetone if MEK not available) or 1300, or 1300L (more solvent). It's yellow so if you use it don't use too much.

I think Lyn is on the right path. Have you tried PVC pipe glue? Oatey has several, including an 'All Purpose Cement' and 'Heavy Duty Clear PVC Cement'.

This sounds like a place where window manufacturers would use ultrasonic welding.

if you want to try solvents, use MEK or MIBK (Methyl Isobutyl Ketone) not acetone. Either should solvate it much better than acetone and are less volatile- I would prefer MIBK.

Try the "Handbook of Adhesives" by Irving Skeist. It is the "bible" of the adhesives industry. Probably available at a county library. Also contact a large vinyl manufacturer or a vinyl trade type organization with your question. They will probably direct you to someone who knows. This is one of the purposes of SIG for products and manufactures of them. Good Luck, Old Salt

Have you tried SystemThree Gel Magic?

I have had success with that - but the mix ratio is critical. Allow atleast 24 hours before stress testing.

You mention thermal expansion -- I used to have an airplane - to stop the windows from cracking at bolt points the holes were drilled oversize to allow for the expansion - aluminum and plastic do not expand at the same rate.

Have you thought about drilling a hole into the frame and using a stainless screw or aluminum pop rivet?

For welding something like that, I'll just take a propane torch and a butter knife, (or something similar), heat the knife, sandwich it between the patch and the substrate, (melting both surfaces), sliding the knife out, and holding the melted surfaces together until they set. It all becomes one piece.

That is the technique used for welding the large sections of the tank at the factory. Both pieces to be welded are pressed against a long hot blade. When heated sufficiently, the blade is lowered, and the two pieces are pressed together.

It almost sounds too simple, but it's always worked for me.

"The 1.5" patches have a T-nut stuck through from the backside (and tabs folded over), so that a 10/32 screw can be used to attach solar screen (< 2 lbs) over windows. Four such attachment points around each window: two at top, two at bottom."

Let's take a step back here and look at the 'base' problem: We need to provide mounting points for four 10/32 screws around a window.

The simplest method would be to install the threaded inserts directly into the framing around the window. You don't want to do this because any penetrations would void the waranty on the window flashing.

The purpose of flashing is to protect a penetration in the siding from water exposure, specifically from water running 'downhill' along the roof or wall.

Small penetrations are typically sealed, not with flashing, but with a flexible silicone caulk.

What we would need for mounting without voiding the waranty, would be an insert long enough to anchor securely in the wood framing, and yet still standing proud of the wall, so the penetration can be caulked without clogging the insert hole.

What we need is a wood screw, probably with a hex head so it can be turned with a wrench, large enough that it could be tapped with a 10-32 hole in the head without compromizing the bolt strength too much.

Hmmm, how do the panels mount? Do they have the screws integral to the panel, or is there simply a hole for the bolt to go through?

If the panels simply have mounting holes, then you just need to get the right bolts, with a wood screw at one end, and 10-32 threads at the other. Mount the bolts through the siding, caulk the bolts to seal the penetrations, then install the panels on the bolts and secure with 10-32 nuts.

I've seen similar bolts used for home 'fire safes,' You drill the pilot hole through the dimple in the fire safe and into the floor, then move the safe out of the way, install the bolt into the floor, set the safe on the bolt and use this big mushroom knob with the nut imbedded in it to secure the safe to the floor. (The know is inside the safe, so if you installed it correctly against a wall, you cannot turn the safe, and you cannot turn the knob unless the safe is open.)

GA! The same thought ran through my mind once (unfortunately, it didn't stop long enough to register) - surely the maker/supplier of these patches should recommend an adhesive, since they're intended to be glued on.

Ta for the reply, I think this is one of those questions where we have to wait for the OP to reply about how they gets on with advice given.

I've nothing more I can adhere (sorry, that is disgraceful wordplay).

Maybe by contacting all those glues, he means getting some on his fingers.

Pick which one suits your needs exactly....sounds like 66 to me....



http://www.eplastics.com/PVC-Vinyl-Glue

ThisToThat: Tells You How To Glue Anything To Anything

The adhesives recommended at "ThisToThat" for this application are mostly what are called "contact cements/adhesives". Several VERY important General rules about using these:

Most of these have harmful vapors that are given off. Unless it specifically says "water based" use a respirator with an organic chemical vapor cartridge on it. Even with this use in a well ventilated area/

For the strongest bond manufacturers usually recommend applying the cement to both surfaces, let them dry to the touch and then place them together, cement side to cement side. This can be very hard since they must be placed exactly where you want them before letting them touch. If you foresee problems with this do the following on a smooth flat surface:

Before gluing the pieces trial fit them to make sure they are the configuration you want. Obtain a piece of Kraft paper, drafting paper or most any paper (not newsprint) that is larger than the pieces to be glued. Separate the unglued pieces and glue them. Let them dry and perhaps give them a second coat. Put one piece down with the glue side up. Place the paper on top of it so that all glued surfaces are covered. Put the other piece on top of the paper with the glue side down against the paper. By feeling through the paper, align the pieces to where you want them. Hold the glued pieces in place while someone else gently removes the paper by pulling the it from between them. Apply sufficient pressure to make good solid contact between the glued surfaces. Make sure this step does not misalign the pieces.

Place force on the assembled pieces with sufficient pressure. Some possibilities are: a rolling pin; a wallpaper roller; rolling a piece of pipe on the surface; Hammer and block with increasing pressure as the pieces stay in place longer; a floor tile roller; between pieces of wood with sufficient clamping force from clamps; bench vise; etc. This step is important because uneven pressure can cause the assembly to "bend". Leave clamped for as long as the directions recommend.

Do some test samples before the big glue-up. Practice, practice, practice! Once you get those glued surfaces touching each other there isn't much of anything that you can do to get them relocated or apart! You're stuck there!

Good Luck, Old Salt

At the risk of further complicating things, virtually ALL vinyl adhesives are mostly solvents, such as MEK/MIBK/Acetone or other equally noxious, volatile solvents. PVC cement is about 80-90% solvents.

I'd not use anything but MEK if I were doing this, but I have years of experience bonding everything imaginable together.

Another problem you might see is the misidentification of the materials being bonded.

That's why testing is always advisable.

I agree that care should be taken when using solvents and solvent laden materials.

Yes, I readily agree with you! In the 70's and 80's there was a push to get away from the usual hexane or heptanes and latex contact glues and switch over to water based formulas. There were some successful ones but most could not be replaced with the water based. Most of these replaced not what they were intended too but lesser quality solvent based formulas. When things didn't go the way they had wanted them to go the push subsided to eliminate the solvent based ones.

Misclassification- Yes, a very big problem! For example- white glue. Not every formulation is similar because it is colored white such as Elmer's Glue-All. Color is not a primary difference between glues. Many of them have dyes and pigments in them. What is important to any user, as you alluded to, is that they obtain good information on what the substrates are, what the adhesive is and then test them on as similar conditions as possible! There certainly is a big difference between the substrates of balsa wood and oak and they glue differently. Take that and at least 10,000 different formulations and you have an excellent reason to test before hand. Test not to what you want but test till glue or substrate failure.

The finished glue application is only as good as the preparations for it.

Good Luck, Old Salt

That's the site I was thinking about, but hadn't looked it up yet. But remember that some plastics are very difficult to get glue to stick to; the cause might have been called surface energy.

However, it didn't cover a problem I have--when the glued parts are soaked in gasoline for years. I have a couple things to try when the weather gets a bit warmer!

You are all asking excellent "fact-finding" questions, and I definitely appreciate both hearing them and answering them (as best I can):

• The window frames & flashings (MI Windows & Doors) are welded-together virgin vinyl which are already installed, so applying back-to-front "clamps" is impossible. The best I can do is either (a) physically hold patch inplace until set or (b) Gorilla Tape in place (sadly very little pressure).

• The PRODUCTS I have already tried with unsuccessfull results:

1) LocTite Epoxy for Plastic

2) LocTite SuperGlue

3) OSI TeQ-Bond Adhesive

4) OSI Quad Adhesive (both Clear and White)

5) DAP StrongStik Adhesive

6) DAP Auto/Marine Sealant (silicone)

7) 3M 5200 Marine Adhesive

8) LiquidNails LN-704

9) LiquidNails LN-702

10) Phenoseal Vinyl Adhesive

11) AZEK Surebond (water soluble pvc cement)

12) Gorilla Glue (both original yellow and new white)

• When I contacted MI Windows & Doors about their "type" of vinyl used, their only response was "...virgin vinyl..." and I got the same answer from TrimQuick ,who makes the thin (≈1/16") 'finish' window striping, from which I cut my 1.5" square patches.

• The FLY-in-the-OINTMENT factoid: need an adhesive 'bond' vice a dissolving 'bond' so as to NOT "void" the MI W&D Warrantee.

• Surface preparation each time has been: (a) clean both surfaces with acetone; (b) roughen both surfaces with sandpaper; (c) re-clean both surfaces with acetone; (d) apply adhesive to both surfaces and clamp. NONE have held up to simple "pull test" after twice the recommended curing time.

Well, that rules out just about anything that will give you a reliable bond.

When you go over the sanded area with acetone, after sanding, does the surface take on a shiny, smooth appearance or does it still look sanded.

It will be critical to have the roughest surfaces possible to produce the maximum "tooth" for adhesion. Adhesive bonding does NOT produce any type of molecular, or chemical bond. It's strictly a mechanical bond, so the maximum amount of surface area and roughness is desirable.

I'd suggest cleaning with isopropyl alcohol after sanding so as not to alter the surface topography of the bonding area.

Also rigid "virgin" vinyl probably has no plasticizers added to it for flexibility. That's good.

I'd try a semi-flexible, not rigid, epoxy. Something with a cured durometer of A 75-90.

That will increase the peel strength.

Have you considered a hot melt with an aggressive tack? It's all solids so this might help.

Good Luck, Old Salt

It's worth a try.

70AARCuda seems willing to do his homework.

What is this "hot melt with aggressive tack" that you mention? Something similar to craft "hot-glue" gun, except intended for pvc and vinyl products?

Oh, and let me clarify my background: I'm a retired EE, not a mechanical engineer (or, as Scotty of StarTrek would say: "...I'm an electron chaser, damn it, not a chemist..."), so I know the general "rules & processes" of problem solving...and, I'm not afraid to do my own "homework" (testing of glue/cement/adhesive samples) BEFORE even thinking about the final application.

Also, the MEK (solvent) approach was actually "banned" by the MI W&D spokesperson because it specifically voids their warrantee, hence the search for a "bonding" method of some sort.

Didn't notice any surface change (dull to shiny) after final acetone cleaning, but will do another test just to confirm.

Hold tight! I will get back in a few hours with a good description for you.

Old Salt

70AARCuda-

A good explanation is at Wiki-

http://en.wikipedia.org/wiki/Hot-melt_adhesive

It is fairly good as general information but not specific to your application. Yes, the most common amateur use of it is in the "hot melt guns" but its most frequent use is in industries. There are a variety of formulas available, each with its own properties, advantages and disadvantages, just like all glues. The properties you would want are adhesion to vinyl, as low a temperature at application, high tack (this is the relative "stickiness" and its ability to adhere to the substrates.

The advantages to hot melts are low VOC's, high solids (as high as 100%), won't weaken with moisture usually, quick tack, quick full strength bonds, available with various incompatibilities and compatibilities, etc. It sounds like a Polyolefin based would be the place to start investigating. The hot melt gun would be a good Laboratory sample applicator for experimentation.

There are many manufacturers: Henkel; 3M; H B Fuller; Google the rest at "hot melt adhesives".

At this point this system sounds the best for you. Many of the formulas are meant for specifically gluing vinyl among other things.

Good Luck, Old Salt

The notable point here is "NOT "void" the MI W&D Warrantee" so if both surfaces are relatively flat, try a double sided tape. There is some that is used by wood turners that is just excellent and I have used with great success on ABS, and PVC. Though it does not seem to like some of the Butyl blends. In Canada we would buy it from Lee Valley and I believe there may be a Lee Valley now in NY? [Lee Valley]

Thanks! I will now do my obligitory "homework" on Hot-melt Adhesives (HMA) by contacting vendors & their representatives with the question "...works on vinyl?"

To be honest, I actually had briefly thought about this approach (wife is into crafts and has couple of glue guns) but immediately discarded it because I have never heard of their use on vinyl materials.

Time to learn something new!

Well, already, one HMA company (ULINE) has said "...no go..." and recommeded that I go back to glues...and use 3M 4475 Industrial Plastic Adhesive.

Which begs the proverbial 'question' of what functional difference is there between 3M 5200 and 3M 4475?

I would be suspicious of any recommendations Uline says about adhesives and sealants. They are not an adhesives, sealant or adhesive-sealant manufacturer. They are a distributor of primarily cardboard boxes. They have nil to do with adhesives. I would even question their knowledge of adhesives for cardboard boxes whether it be dextrin, PVA, EVA, hot melt or just about anything else. They may also steer you to some products they sell instead of the best for your application. As Wiki saysà

Uline is a distributor of shipping, industrial, and packing materials to businesses throughout North America. Uline distributes more than 25,000 products...

Adhesives and sealants combined products are a compromise. They aren't an excellent adhesive or sealant. They have properties of both and can be used where both properties are required but they can't do either really good. For example, when you have flexibility such as with a urethane based you may lose adhesion. A generality is that for the properties of particular water or solvent based glue there is a hot melt adhesive that could take its place.

My suggestion would be to keep on searching. Stick with the adhesives, sealant or adhesive-sealant manufacturers. Don't bother with the sales personnel. Speak to the tech service or development lab people. They are the ones who really know what does what with substrates and adhesives. If you contact one that doesn't make a suitable product, ask them for a recommendation of who might. It is generally a very completive business so they will be open about this because they want your future business for a product they manufacturer.

The products that Uline recommended are marine sealants. Some people who have used them for boats don't think they are very good. Although these are sites about boats they may be of interest to you:

http://forum.woodenboat.com/showthread.php?169541-epoxy-or-3m-5200

http://forums.iboats.com/boat-topics-questions-not-engine-topics/3m-4200-vs-5200-thru-hull-applications-253873.html

Also I spent many years in the adhesives business.

Good Luck, Old Salt

I get Uline catalogs and throw them in the round file.

3M 4475 is for use with flexible PVC, which 70 does't have.

Long shot but have you considered the cleaner (MEK) and glue for PVC pipe. Use the clear cleaner, not the purple, and then PVC pipe cement. Worth a try. They are both a form of vinyl.

Good Luck, Old Salt

Plastic welding is so easy , even I can do it. I have some 4,500 gallon rectangular water tanks mounted on off road trucks that come with lifetime warrantys. They are repaired with a glorified soldering iron that has air blowing through a hole in it. The technique involves blowing hot air, or nitrogen onto the area that needs welding. Like solder, the plastic will get a sheen to it as it starts to melt. You then add filler to the heat and allow it to adhere to the existing part. In your case, I would hold the edge of the new patch to the correct location at 90 degrees and heatthe edge where they meat. Slowley heat and roll the patch into place while heating the surfaces as they come together. Like rolling a patch onto a tube to be repaired. Good luck.

If we're into welding . . .

70 said he's trying to attach a t-nut. Why not just heat the nut to the proper temperature then press it directly to the vinyl flashing - sort of like stud welding? Roughen the surface of the nut flange before-hand, maybe even drill some small holes in it and let the vinyl extrude through. He could then go back and reinforce it with his patch, if needed. But, I expect this whole thermal welding approach to meet the same objections as the solvent welding.

Melting the T-nut into the plastic requires more material thickness than we have here.

Melted plastic won't stick to metal, for numerous reasons. Normally this is done with molded-in bosses that are melted to capture the item being staked.

I know I sound like a know-it-all, but I've used this method before, too.

So far, hot melt or welding seem better than other methods we've discussed.

We won't even talk about Induction Welding - TWI

Has anyone tried using one of those ultra sonic foggers? They are small hockey puck shaped units you can place in ponds or pools and powered by 24 VDC they create a foggy mist. They are also used in some humidifiers. I found by touching the active element you can get a powerful burning sensation.

I haven't taken mine apart yet but I was thinking if you could get the element exposed where you could press it against a surface you could do "ultrasonic" spot welding.

Are the solar screens rigid? Forget glue for all the reasons being mentioned, use clips or wing nuts like from the 20th century.

http://www.amazon.com/Window-Screen-Clips-White-Plastic/dp/B000KZYI9Y/ref=sr_1_8/189-6896917-9935519?ie=UTF8&qid=1391832063&sr=8-8&keywords=window+screen+clips

RTV?

I'm not sure I know what this patch looks like, but if it is mechanically attached, then maybe you could just run a bead of silicone around the edges to seal it. Silicone expands and contracts, which is why it is used whenever there is a 90 degree angle when installing tile. You could also post this in the chemical engineering section.

How about this 3M VHB tape:

http://solutions.3m.com/wps/portal/3M/en_US/Adhesives/Tapes/Brands/3M-VHB-Tape/

Partial rolls can be found on eBay if you only need smaller quantities.

Or request a free sample.

-Mike

I have also used a variety of 3M tapes. VHB is excellent, but I think there are a family of VHB formulas. Contacting 3M would be best for this I think.

Another source of information on plastics would be US Plastics. As big a catalog as Uline, but all they deal with is plastics. All kinds of plastics. They should have some answers. Good luck.

A double sided tape is your answer, caarelessly applied it would hold the weight, carefully applied, way more. 3m's vhb as mentioned, is probably the best, certainly the most famous.

But of course it relies a bit on surface area. You may have to rethink the part you are sticking on, which may mean you can get rid of the vinyl patch and just have a metal disk with your threaded part already mated to it. Have a look at www.bighead.co.uk fasteners. You can design your own!, if you make the plate thin, it can be bent enough to get the fixing off at any point.

cnc

It beggars belief that someone at 3m said we can't stick vinyl to vinyl.

What about HH66 Vinyl Cement? It says it is a "fast drying (2-5 minutes), waterproof, solvent-synthetic, resin adhesive" that dries hard and is very strong, but is flexible, and not affected by weather and temperature extremes. It costs about $6 for 4 ounces. I would call them with your application before buying. Whenever I call a company with a technical question, I ask to speak to someone in "technical services". Customer service and sales people are a waste of time. Hope this works for you.

We-l-l-l-l-l, just got a "...use epoxy..." instead of HMA inference from one of the companies representing 3M, specifically "...use ResinLab EP1056LV..."

The Bostik representative recommended their Thermogrip 6239 polyamide Hot Melt Adhesive, but buried in the data sheet fine-print is this troubleseome statement: "Note: Polyamdies slowly absorb moisture/humidity from ambient air which may cause foaming upon melting of the product. Care should be taken to minimize moisture exposure." ...and, my exterior window siding applications see a LOT of water during summer monsoon storms.

Q: How are the flashings installed? A: they are literally "glued & screwed" into place: (a) OSI Quad clear sealant is applied to the backside of the flashings to 'seal' the flashing against existing wooden faux-shutters (but is NOT working 100%), while (b) four 4"-long interior screws are the primary mechanical "fasteners" holding the whole assembly in place. Behind the flashings is only the faux-shutters, any screw-holes will leak water directly into a ~1" air-gap between the old wooden window framing and the new vinyl MI W&D assembly.

Am also (now) looking into that 3M VHB 'tape'--stuckum on both sides of a thin foam core tape, as I recall.

A word about polyamide. DuPont Company invented polyamide resins in late 40's/early50's. They called it Nylon®. So, it's a thermoplastic polyamide. Epoxies are also polyamides, but they are thermosets. (Don't melt)

The point is it only foams viods if 1. it has absorbed moisture and 2. you melt it, which you'll have to do to apply it.

When we molded thermoplastic resins, we dried them for 4 hours at 250°F first in an oven or resin dryer. So, don't necessarily rule our the Thermogrip, but it should be tested first to see if it foams. If it doesn't, it's OK to use. After it solidifies, it will still absorb moisture. That's not too bad. All Nylons do this. All plastics do this to some degree, as well.

More than you wanted to know.

The tape will work, but do peel tests because the foam will probably fail before the bonds.

I'd still weld it, somehow. Then, there is no bond line to fail.

I also think foam tape will work, but the life will be limited outside, in Arizona. I predict that the foam will fail and you will have tape left on both surfaces. This tape is made from a layer of clear two-sided tape, a layer of foam, then another layer of two sided tape. It's made on rolls several feet wide, then slit to width.

Ok, I'm done now.

Most solvents designed for PVC are of the Methyl Ethyl Ketone/Tetrahdrofuran family, similar to PVC pipe joint solvent and yes it is somewhat moisture sensitive as the presence of moisture will hinder the evaporate. Though once set it will be moisture proof. Another in this group is used by PVC window manufacturers to repair stress cracks or joint failures. I don't recall the trade name or composition but I am sure a window fabricator might be persuaded to give you a nearly empty tube that you can use quickly (Tip: Ask on a Friday afternoon as these tubes go solid quickly once opened and better to give good-will than throw the expensive stuff away on monday morning) Adhesive relies on the covalent bond between the PVC and the adhesive and the other mating surface. In this family there are very few, after all, PVC makes a very good external cladding for homes simply because very little will stick to it!( except of course dirt after the siding has been washed with acidic rain) Many PVC bonding solutions require a primer to be applied which has the effect of etching the surface to create a more mechanical bond. Then there are the "sticky" adhesives, the high tack adhesives. some are permanent such as the Polyurethane tape that is used to bond shower stall sections together. These are hygroscopic - they cure in the presence of moisture, while others are non permanent such as was described in #35 comment earlier. Finally you have the choice of mechanical fasteners but these will leave holes.

There are no covalent bonds between adhesives and substrates. None.

There are attractive forces, referred to as Van der Walls' force, and are they much weaker than covalent bonds.

OP has stated that solvents will invalidate the warranties.

No covalent bonds? not even between water in concrete or isocyanurate and water on FRP? really. and as for the warranties, I covered that in comment #35.

Don't get your panties in a wad.

You said, "Adhesive relies on the covalent bond between the PVC and the adhesive and the other mating surface."

I said, "There are no covalent bonds between adhesives and substrates. None."

There are, still, no covalent bonds between adhesives and substrates. None, never.

Don't get your panties in a wad.

Wedgie

There are foam centered tapes, but I would reccommend a solid, they both degrade due to uv, but if it behind a metal plate, you are ok

cnc

An idea occurred to me today:

Why are we trying to find a way to bind these too-small patches to the window frame at all? Why don't we just look outside the window frame and attach supports to/in the WALL itself, and have those supports reach in to provide the mounting points required for the ... solar panel, was it? It is easy to drill through siding to reach the studs behind it, and also easy to seal the openings. Since the window frame is not touched, then the warranty is still valid.

Have you had a chance to pour over this link?

http://solutions.3m.com/wps/portal/3M/en_US/Adhesives/Tapes/Products/

Vinyl panties? Unfortunately, not what I'm working with (darn it)...which are vinyl flashings, not vinyl flashers (ha,ha).

You will arrive at a satisfactory solution because you take the time to investigate the options.

Haboobs are coming. Then, well see.

Timing is everything. Or so they say. Today IHS Global Spec sent this along. Hope it helps. Please note they offer some samples at the end of the video. Might be sufficient for your needs. Good luck. Bob.

http://www.youtube.com/watch?v=Hazqpm_uyYI&feature=player_detailpage

Several things are obvious after reading all the replies and further info from 700AARCuda.

The square fasteners have a 1.5" on-a-side length producing just a little over 2 square inches surface area.

The attachment method was meant to utilize a covalent bond, however, the window manufacturer effectively forbids this if one wishes to maintain the warranty.

Adhesives use Van Der Waal forces, which are much weaker than covalent bonds. Therefore a much larger surface area is required to compensate. Therefore the fasteners must be modified to have that larger surface area in contact with the window frame, and/or the number of fasteners must increase proportionately.

I would recommend that the fasteners use a vinyl interface layer to reduce expansion differences across the adhesive. Might as well make it at least as thick as the original T-nut depth, probably more. I also recommend keeping the machine thread near the center of each new larger part - even if that means the part has to turn the corner of the window frame.

You may need to limit the size of the new parts so that they do not flex significantly (under load), or use more screws on each part. Bending would tend to concentrate stress causing early delamination.

At the upper limit, you may create an adhesive interface as large as the window frame, with many more screws to distribute the forces.

The surfaces should NOT be abraded with a course or medium grit. A very fine grit will allow pressure sensitive adhesive to conform more completely. An orbital sander will produce a cross pattern with more active area than does parallel sanding.

I also agree that isopropyl is better than stronger solvents at keeping the vinyl surface strong.

Solvents interfere with adhesives. Allow plenty of time for the cleaning solvent to escape from absorption in the vinyl.

Dish detergent, distilled water, and dry steam may be effective cleaning agents to remove sanding dust, oil, and contaminants.

Do not use rags that have had contact with fabric softeners (like inside clothes dryers). Your skin is another source of oil contamination.

I have these vinyl curtains that the cats keep poking and ripping. This 3m duct tape works well by 3m and it comes in different colors. I bought the white one. Be careful once you put it on you might not be able to take it off without ripping the vinyl! It cost me like $5

Use H-66 Vinyl Cement. It is superior quality adhesive which dries very quickly. It is widely used to bond vinyl coated and vinyl laminated fabrics to themselves and to other various materials.

Yes. Heat. The material can be welded.

I think I would just go another direction and use brass grommets and screws and seal it with silicone...then plug the holes with nylon inserts...