Some of the specs that I'm reading online say that VHB's operating temp is between 50 and 300 deg. Is this true or am I reading the specs of a different product than the one you're using?
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Some of the specs that I'm reading online say that VHB's operating temp is between 50 and 300 deg. Is this true or am I reading the specs of a different product than the one you're using?
There are different VHBs. WV probably knows them all better than I do. What I think you may be looking at for the low is the application temp:
Quote:
Ideal tape application temperature range is 70°F to 100°F (21°C to 38°C). Initial tape application to surfaces at temperatures below 50°F (10°C) is not recommended because the adhesive becomes too firm to adhere readily. However, once properly applied, low
temperature holding is generally satisfactory.
From the spec sheet from this site: http://multimedia.3m.com/mws/mediawe...709-3862-9.PDF
You will have to look through the document to see the graph. But simply stated the tape is tested to -50C which is -58F.Quote:
The VHB™ Tapes have also performed well in tests, similar to MILSTD 883, which
are commonly used to qualify durable products for the electronics industry. Under
this testing, protocol bonds are subjected to 1000 hours at 150°C, 1000 hours at 85°C
and 85% relative humidity, and 1000 hours of thermal shock which cycles hourly
from -50°C to 150°C. Figure 3 shows the excellent performance of the VHB™
Adhesive Transfer Tape F-9460PC in similar testing which involved bonding
polyimide to aluminum. Typically the bond strength increases with time due to the
high performance PSA’s more complete wet out of the surfaces.
50 degrees is the lower limit for applying the adhesive in F9460PC. Once the bond is established, it's very strong. These are quotes from 3M technical bulletins.
AlsoQuote:
These VHB adhesive transfer tapes are made from the same adhesive system and are
thermoplastic in nature, becoming softer as temperature increases and firmer as
temperature decreases. As the adhesive becomes firmer, the adhesion performance
generally increases. At low temperatures (lower than -40°F, the VHB adhesive
transfer tapes become very firm and glassy; the ability to absorb impact energy is
reduced.
Sarge, you're too fast for me!Quote:
The VHB™ Tapes have also performed well in tests, similar to MILSTD 883, which
are commonly used to qualify durable products for the electronics industry. Under
this testing, protocol bonds are subjected to 1000 hours at 150°C, 1000 hours at 85°C
and 85% relative humidity, and 1000 hours of thermal shock which cycles hourly
from -50°C to 150°C. Figure 3 shows the excellent performance of the VHB™
Adhesive Transfer Tape F-9460PC in similar testing which involved bonding
polyimide to aluminum. Typically the bond strength increases with time due to the
high performance PSA’s more complete wet out of the surfaces.
Sergent Rock
As I was reading this thread, I was wondering if the tie outs could be made of doubled over Cuben strips that then get taped on to the edges. Since they would be made at home, they could even have larger ends than the strip part. This would add strength to the adhered part and minimize the number of pieces.
I have not ever used CF but have been doing research recently.
Thanks for the great video.
I thought of that. One thing cuben does not stand up to well is abrasion and I assume where ever the pull out meets the cord there will be a lot of abrasion. That is why I didn't try it.
Something that might be worth doing is taking a piece of cuben and encasing it in something resistant to abrasion (ripstop or cordura, maybe?) over the majority of its length, and then taping the end pieces to the tarp as the tie-outs.
See stupid little ascii graphic below for what I mean:
-: Ripstop (sewn to itself to make a sleeve for the cuben).Code:----------
====================
----------
=: Cuben (taped to tarp at ends to make tie-out "skeleton").
The cuben provides the immense tear strength that cuben is noted for, along with an easy attachment method that doesn't perforate the tarp itself. The ripstop (or cordura, or...you get the idea) provides the abrasion resistance versus the guyline that the cuben can't.
Just a thought.
Or perhaps pulling some cuben through a tube of some sort and then gluing the two ends of the cuben to the tarp...
It could work. I would suggest 5" x 1/2" wide cuben run through the shell of paracord. I would tape 2" at each end to give a good weld to the tarp and use the paracord to protect the 1" of cuben where the tie out meets it.
When "3M 9460" was searched, a PDF file of 3M Technical Data showed some application tips on page 4 of 4. A clean surface was recommended with the cleaner being isopropyl alcohol/water or heptane. Let's talk about those two cleaners.
Isopropyl alcohol is the chemical name for rubbing alcohol. The drugstore has it in 91% and 70% alky/water ratio for about a dollar a pint. IIRC, isopropyl absorbs water vapor from the air so it is never 100% alcohol. No, you do not need to thin it with water, the water mentioned is just already in there as it comes out of the bottle. My opinion is that is an inexpensive cleaner if it is suitable for the cuben.
Heptane is a refined petroleum product like a super clean gasoline and likely smells that way. Not a pleasant solvent to work with. I'm guessing that is what the stinky "94" 3M solvent is. My question is, is 94 necessary for cuben, or is that just 3M upselling their product when cheap iso alcohol is adequate and smells slightly better?
The application tips also mentioned pressure would improve bonding so Sgt. Rock's use the roller not only pushes out bubbles but matches 3M's bonding advice. At BPL forums, Steve Evans weights/squeezes his bonded seams while they cure for a period of time. As an engineer, he may even understand some of that lingo on the tech data page.
As part of the same Google search, Amazon.com has 36-yard single rolls of half inch, 3/4 inch, and one inch wide 9460 tape for $25/$36/$49 from CS Hyde with free shipping. RS Hughes is not the only retail source. A case of each type of tape is over a thousand dollars direct from 3M.
Just telling you what I saw on the internet.
Heyyou, thanks for adding to the knowledge base. I believe Primer 94 is more than just a solvent, though you may be right about the solvent that is in it. The instructions advise to shake it well before using it. Also, when I was doing pull tests with 2" x 5" strips of CT3 I laid them out on a scrap of formica and used a paint brush to apply the primer. Some primer got on the formica around the edges, but it dried clear and wasn't sticky, so I left it. Now I can see clearly where the strips were because the primed formica collects dirt.
When I bond a seam with 9460 and primer I use blue painters' tape to mask the area of the bond while applying the primer.
Your question about the necessity for primer is a good one. My tests showed that the bond with 9460 and 9469 is significantly stronger with Primer 94. Primer also improved 9482 and 9485, but only a bit. If you don't use primer, 9482 and 9485 are a bit stronger than 9460 and 9469. For many uses 9482/9485 would be fine. 3M says that Primer 94 also increases peel strength. All my tests were for shear stresses, such as a tarp seam would be subject to.
Nice to hear that Amazon has these tapes. Compare prices to Uline.com.