- Feb 12, 2018 at 8:27 pm #3518029
Has anyone successfully seam taped a backpack with the X-pac X-21 RC fabric, which has a PET film inner lining?
FYI, Nick at Dimension-Polyant recommended “3M transfer tape 9485PC”. However, I can find no MYOG info about using this particular tape, plus it’s rather expensive and difficult to find in small quantities. Also, Quest Outfitters suggested that their Mylar tape may work with X-21 RC, but they are uncertain.Feb 12, 2018 at 8:54 pm #3518033
3M9485 is a Transfer Tape. Read up about them. This particular one is very highly regarded, and is used by quite a few of ‘us’ (including me).
Yes, it may be dearer than some others – you get what you pay for. Just buy a roll of it and use it – you won’t regret it.
CheersFeb 12, 2018 at 10:12 pm #3518050
Mike BBPL Member
No personal usage of the product but I am getting more and more interested in MYOG and if I do not have to use a sewing machine as much all the better. So I will be watching this thread. It is available on Amazon by the roll https://www.amazon.com/3M-9485PC-Clear-Transfer-Tape/dp/B000V4L3Q0/
For the tech minded of the bunch https://multimedia.3m.com/mws/media/66399O/3mtm-adhesive-transfer-tapes-w350-adh-9442-9445-9485.PDF
MikeFeb 13, 2018 at 12:32 am #3518085
I have used 3m 9482pc for all my tapeable projects, including Cuben tarps, and it has been wonderful. And yes, I have seam taped X21rc with it. The pack project I posted recently was taped with it. I made Cuben tape with it and taped the pack with that and it’s holding up great.Feb 13, 2018 at 2:44 am #3518118
Luke MBPL Member
When y’all say seam taped, that means bonded solely by adhesive and no stitches, right?
want to make sure I don’t spend $30 on a roll of seam sealer.Feb 13, 2018 at 2:47 am #3518119
@luke-farlane No, the seams absolutely have to be sewn. The tape is only to seal the seams for waterproofness. You could fully tape the seams on a 1.43 osy Cuben (DCF) pack but definitely not with x-pac.Feb 13, 2018 at 3:31 pm #3518173
Ryan SmithBPL Member
I’ve got oodles of 9485pc in 1/2″ width and 9460 in 1″ width. I’d be happy to send you some if you don’t want to buy a full roll.Feb 13, 2018 at 5:53 pm #3518189
Thanks everyone for the info. It looks like the 3m 9482PC and 9485PC are identical except for thickness (0.05 and 0.127 mm thick, respectively). After watching videos on “transfer tape” used for vinyl craft projects and reading several websites, it’s still unclear to me how exactly to use either of these tapes to seal a backpack seam. 4 questions:
Feb 13, 2018 at 6:54 pm #3518197
- It appears that these tapes are single-sticky-sided, and that the “tape” is actually sandwiched between TWO “backing” layers – one backing layer that’s removed to expose the sticky side of the tape for application, and another backing layer that you peel away when done applying the tape, to leave the tape behind. Is this correct?
- Do you simply apply the tape to the seam while removing the 1st backing, press down with a credit card to activate the pressure-activated adhesive, and then remove the 2ed backing to leave the clear tape stuck to the seam?
- Some websites advocate using variable degrees of heat, depending on the tape and material – do you use these two products at room temperature or with heating?
- Is the 0.75 or 1.0 inch width best for taping seams, including flat felled seams made using 5/8″ seam allowance (finished seam width of 3/8 inches)?
- When you pull the tape away from the roll, one sticky side is exposed. Once that side is adhered to something you peel the backing off to expose the other sticky side. Here is the part you’re missing, you need to turn that double sided tape into single sided tape if you want to seam seal with it. I like to use cuben, specifically 1 osy. Just peel the tape away from the roll, just like scotch tape, lay it down nice and straight on the cuben then cut that strip off once you have the length you want. The result is single sided tape with cuben on the face and a paper backing that you peel off to expose the adhesive. Picture a sticker, where instead of someone’s logo, it’s cuben fiber. peel the back off and it’s basically a cuben fiber sticker that you apply to the seam. That make sense?
3. I’ve never used heat and never had any issues. I DO use a hard rubber ink brayer from Hobby Lobby as a means to apply pressure to the adhesive and get any bubbles out.
4. I would definitely recommend 1″ for sealing a backpack.Feb 13, 2018 at 8:03 pm #3518206
Thanks Hoosier – your single paragraph explanation clarifies the entire process perfectly.Feb 13, 2018 at 8:52 pm #3518218
NP and glad to help. It’s nice that RSBTR sells DCF by the half yard. Using 1″ tape, this would give you 18 strips of 54″ DCF tape (requiring 27 yards of tape). Use whichever DCF you wish. I use 1 osy because I prefer to have the tape assist with seam strength so I don’t bother with felled seams on the pack. The tape will prevent the seam from busting open but I do like the slightly stronger DCF for that purpose.Feb 13, 2018 at 9:06 pm #3518219
I prefer to use a light proofed nylon fabric instead of DCF, but that may be because I have a lot of proofed nylon around :)
But always make up the ‘sealing tape’ first, rather than try to apply the transfer tape to the pack first.
CheersFeb 14, 2018 at 7:51 pm #3518376
We’re working on a seam tape for permanent bonding for XPAC fabrics, no sewing required.
Stay tuned. I’ll drop a note here when it is available.
TaylorFeb 14, 2018 at 7:56 pm #3518377
Sounds interesting Taylor. What’s your approximate time frame? And will this be for the PET backed fabric (X21 RC) or the woven nylon backed fabrics (VX21, VX07, etc)?Feb 14, 2018 at 9:00 pm #3518389
I’m hopeful that it would work on bot the nylon face fabric and PET film. We need to do some testing and work on logistics but with any luck it would be available in a month or two.
TaylorFeb 14, 2018 at 11:43 pm #3518426
Wilderness ThreadworksBPL Member
Indeed, very interested to hear how the testing of this seam tape pans out Taylor.
Cheers, Dan.Feb 15, 2018 at 3:48 am #3518474
In theory I like the idea of a no sew bonded seam, but in practicality it seems harder to achieve even with a perfectly formulated bonding tape. Unless the design is very simple like a roll top dry bag, I would think critical seams incorporating pack straps, webbing loops, etc, would still make it hard to go without sewing?Feb 15, 2018 at 4:56 am #3518487
Yes, I have pulled out a few bits of straps/webbing, even with sewing. The fabric itself could not support the load: too much of a loose weave.
CheersFeb 15, 2018 at 7:59 am #3518493
Come to think of it, most dry bag style packs have external straps and hardware attached via large bonded patches rather than at traditional seams, or else they’re held in a totally separate harness like the ULA Epic.
I too have experimented with the 3m9485 to waterproof seams on X-pac, but due to the cost and hassle, I’ve tested a variety of other tapes, glues and sealants. Everything from straight household caulking to duct tape. 1″ Gorilla tape will actually work okay in a pinch as a temporary fix. Sometimes I have to ask myself why I’m perusing this allusive goal of perfect seam sealing. Used to be, I’d just throw my sleeping bag and clothes in a trash bag at the bottom of my unsealed pack, put anything else sensitive in a ziploc, and never really had a critical problem even in multi day downpours. At that point, humidity and condensation is the true enemy anyway. No matter how much effort I put into bomb proof seam sealing, I’ll probably never leave behind an emergency trash bag and plenty of ziplocs.Feb 15, 2018 at 8:24 am #3518495
Um, well, it depends.
When I am using a tape-sealed X-Pac bag, I don’t worry about rain or crossing rivers. I will use a garbage bag as well if I am going to be swimming for some distance with my pack. In heavy cold rain I have my poncho over me and my pack as well.
That said, I should mention that everything inside my pack is in waterproof bags anyhow. A light plas bag as you might get fruit in at a supermarket, inside a silnylon bag, done up in a waterproof manner.
Yeah, paranoid. But this paranoid has never had wet gear.
CheersMar 23, 2018 at 3:22 am #3526472
A W TBPL Member
How’s the tape coming along? Can’t wait!Apr 13, 2018 at 3:17 am #3530257
Brook QBPL Member
This is a laptop cover case I made with X21 RC. :-)
Then in this situation the cuben is only used for “peripharal pupose”: taping.
The first thing is to make the single side cuben tape by using the 3M VHB series (9460, 9452 etc. whatever is called). Here in my location, it’s very easy to get the tape in any width. So here for example I made 1) 18mm tape with the .74oz cuben for the purpose of the seam sealing typically seen in a gore-tex jacket and 2) 40mm tape with the 1.43oz cuben, for the top rim finishing special method that uses the tapable feature of X21RC. I made 40mm wide tape because it also cover the Velcro sewing, so you finally don’t see any outbouding sewing thread in the project, which is my typical style. :-)May 25, 2018 at 7:26 am #3538270
A W TBPL Member
Just following up to find out how the seam tape is coming along.May 25, 2018 at 8:24 am #3538272
Taylor has sent me a sample to test out with the fabric samples he sent some time ago. I am waiting on the instructions for use: temperature, pressure, what it will bond to, etc. I found the 3M9845 did not bond to well to the DWR-treated face fabrics on the light VX series.
CheersMay 25, 2018 at 5:36 pm #3538346
We have some sample rolls of heat activated seam seal tape available.
Roger, I send you an email reply this morning. Let me know what you think.
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