Not that much work. I've been sitting on these for the better part of a week, trying to figure out the best way to present and publish. As we're approaching the shipping time limit for people to obtain their materials in time for this year, I decided to put this out as is, even if it's not in an optimum form.
I don't have any feed back for use of pro-gaff tape in on-playa temperatures.
jkisha wrote:...Do you know if the strength/adhesion is effected by heat?...
But you raise a very important point, and one I've been struggling on how to write up. We need to caution that for on-playa use, we're not going to get the full holding strength from tapes
. Different tapes will have different strength retaining properties under playa heat. Like most of the 'duct-tapes' letting go under heat and wind load, or some let go just under heat, curl up and blow away (some swear they hear them whimper... or maybe that was their camp mates standing behind them). Some "professional" duct-tapes have succeeded on-playa, and some have not. If you're going to count on any tape, you have to have reliable feedback that they held up under both the heat and the winds of the playa.
The adhesion specification provided by the manufacturers is for adhering to stainless steel or clean steel in lab conditions at room temperature. That's all I can find published.
Between playa dust (or at home, dust or panel cutting debris) on the panel or blown onto the tape just before it's applied, old dirt or finger grease on the panel surface and elevated playa temperatures, we're not going to get the same level of adhesion as is reported in labs. So on a practical basis, we can't know what the actual holding strength will be on the panel's foil surface, but we can see how much less strength various tape widths or tape choices will provide. So, once again, the tried & true Playa-Tested©)'( trumps everything we can calculate.
Beyond a yardstick between width and tape choices, it can also show us why the six inch wide bi-filament yields the most successful on-playa results. Like it's tolerance to mis-alignment when applied (meaning you don't have to get it aligned perfect to get good strength) and we can expect the same for losing a little bit of square inches of holding due to a little bit
of dust. It is interesting to note that a 75 mph wind delivers up to 28 lbs./sq.ft. for 450 lbs. of force on a 4'x4' panel, or 900 lbs. of force on a 4'x8' panel. This 6" wide bi-filament tape, even when mis-aligned by up to 3/4", still calculates as strong enough to take that entire load on a single length of joint, and in practice, that force on the panel will be shared among three joints. So with the decreased holding strength due to the factors noted above, we can reasonable expect that 6" wide tape to do the job. And reports from the playa support that.
To ball park it:
Which pretty much reflects what people report as what happened on-playa:
- the 6" wide bi-filament tape yields strengths exceeding the 75 mph wind maximum loads,
- the 4" wide shows numbers in the range of those loads, and
- the 3" wide tape is below those loads.
And that's with the 220 lbs. | 91 oz. bi-filament tape.
- 6" wide = almost always good (application dust & errors unknown)
- 4" wide = usually o.k.
- 3" wide = often not o.k.
Use weaker tapes and you've got poorer results.