Bushwalk Australia

Hi all,

Last night I started making a packraft. It's a project I thought a few of you might be interested in, so I've started this thread to document its construction.

I've wanted a packraft for some time now but the cost has always kept me well away. I was filling in some time googling last month, when I came across a site dedicated to making your own packraft (diypackraft.com). As you could imagine, I was pretty chuffed when I found out that someone had already made a packraft themselves and were offering plans for $20 USD! So logically I opened my wallet, bought a set of plans and fabric, and waited eagerly for them to arrive in the mail

I'm using 40 denier, Ripstop Nylon so it's going to be a pretty lightweight raft (well under 1 kg I would think). I'm planning on making another one down the track (if this one comes together alright) made of a heavier material (210 denier Nylon which is similar to what Alpacka rafts are made from). It should cost around $200 all up + time, which I think is pretty neat.

If people are keen to see some initial photos, let me know and I'll upload them tomorrow.

Love to see photos of projects. Please share

Very interested please.


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$20 well spent, please do post back with progress and testing. Self bailing seems the direction others are heading, may be easy to incorporate?

Haha, I was about to ask if the plans supported self bailing.


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Ha! I thought about doing this 10yrs ago, but started with a DIY lightweight lilo type arrangement using plastic bag tubing for the air compartments (the hard bit was trying to put a "valve" arrangement on each tube), inside a nylon outer (making an 8" thick lilo with 5 air tubes). It actually worked well, and was reasonably light, but a raft looked so much more fun, and I just bit the bullet and bought an Alpacka. The beauty of the Alpackas is that they are almost indestructable - the polyurethane material is extremely scuff resistant, and we have not had any punctures despite some pretty significant scraping on rocks in NZ.

I hope the project goes well, and would love to see some pictures. I'm interested in what you are going to use for a valve, and how you attach it, as that was the main thing that stumped me.

A

andrewa wrote:I just bit the bullet and bought an Alpacka.

A

What model did you buy andrewa?


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This has to be the most ambitious MYOG project posted here. Photos, please!

Nuts wrote:$20 well spent, please do post back with progress and testing. Self bailing seems the direction others are heading, may be easy to incorporate?

I'm not going to worry about self-bailing with this one. I haven't got any whitewater skills as of yet, and this boat will mainly be used on calm water so I think it would be more of a disadvantage than advantage to have. I also didn't want to over complicate things first up with the materials/techniques etc. being new to me.

It will definitely be something I consider when making my more heavy-duty second one though. From the videos I've seen of people modifying their rafts to self-bailers, I think it would be very easy to do with this design (e.g. with reference to Mark Oates' video https://vimeo.com/156952675, baffles could be easily bonded to the floor using the TPU-outside option explained on the diypackraft.com website).

andrewa wrote:I'm interested in what you are going to use for a valve, and how you attach it, as that was the main thing that stumped me.
A

Yes, I read about your previous attempts when doing my research!
The valve I'm using is called a "Boston valve". The bloke I bought the plans off used this type on his, and sells them on his site. It only cost me a few dollars and was proven so I didn't think a lot more about it. When I make my next raft I will give the valve more thought though. The Boston valve looks good, but it also sticks out a bit from the boat. Positioning it behind your seat would help lessen the chance of impacts, but I think I would be a bit concerned about it being ripped off/damaged if something happened to snag it.

north-north-west wrote:This has to be the most ambitious MYOG project posted here. Photos, please!

Nah, nuts' cuben mid that he posted a while ago takes the cake for me. THAT was impressive. The website that I bought my plans from is well set out and has made the going pretty easy to date. Hopefully there aren't any hiccups around the corner

I'll put some photos up now of where I'm up to.

Unfortunately, I chose black fabric for this raft which meant that when placed on top of the template, the lines below were no longer visible! To get around this I had to cut out each of the different shapes beforehand. I could have just cut up my original plans, but I didn't want to destroy these (given I will be using them again for my next raft) and all my previous plans have come out mangled by the end of projects...so I taped lots of A4 pieces of paper together to make a massive sheet and a new stencil.


Once I'd stuck all the pieces together, I traced the pattern onto the new sheet...

...and cut them out and placed them onto my packraft fabric.

If anyone gets around to making one of these in the future, I would recommend pinning your fabric/stencil down with books before tracing. The books help to keep the stencil in place (always annoying when it moves halfway through tracing) and they also help to keep the fabric nice and taut.

I have found chalk to be great for marking out slippery, old nylon. I'm yet to find something that is as easy to apply, visually distinct and non-marking/easy to get off again.

The next part was to cut it all out. You have to do this twice - once for each half of the raft. This was a pretty painstaking job and I was glad to have this behind me and be onto the welding.

This is my high-tech welding station I was a bit worried about which way to go with this originally as I had heard others say that you need a temperature controlled iron. Thankfully, this $8, 25-watt soldering iron has done a great job so far. Other than moving the tip end in/out, you can't control it's output but I haven't had too many issues with it. If it's been sitting hot for a while, I've been rubbing it on some cardboard before using it to stop it from singeing the nylon...but you soon workout what works and what doesn't. It also came with a flat, spade-like tip which was very convenient.

To keep things cheap, I knocked up this iron holder out of an old spaghetti can. I filled it with pebbles to stop it from being knocked over.

Below is one half of the raft ready to be welded up.

Curved seams have to be welded against a curved surface (at least initially) so I've been using this old riding helmet for the job. The padding on the bottom also works well as a non-slip surface.

This is pretty much where I'm up to at the moment with the raft - I've done two curved seams on one of the halves. So far it's come together really well and I've been very happy with the results. Once I've done some more work on it, I'll upload some photos with some padding under the fabric so you can appreciate the three dimensional appearance it's starting to take

For Andrew's reference, this is the Boston valve I've got. The first photo shows it all done up. In the second it is separated into its different components. The fabric goes between the bit where the pen is placed i.e. the rubber ring/band is glued to the inside of the tubes. Hope this helps.

Awesome! Thank you so much for the pictures and the detailed explanations.

Can't wait to see how this turns out. Very ambitious project, but you clearly have the tenacity to see it through.

Fascinating. Are you just welding normal nylon, or is it a particular sort of nylon?

Keep the photos coming!

A

andrewa wrote:Fascinating. Are you just welding normal nylon, or is it a particular sort of nylon?

Keep the photos coming!

A

Will do! I've almost finished welding together all the curved seams so next step is to turn them into tubes.

It's ripstop nylon with a thermoplastic polyurethane coating. This is the stuff that I bought http://www.extremtextil.de/catalog/Ripstop-Nylon-40den-TPU-coated-heatweldable-70g-sqm::2870.html

Admittedly, I have taken a bit of a gamble here because it says that this fabric is "not suitable for prolongued use in humid conditions (i.e. objects that are inflated by human breath) or prolongued exposure to sunlight. Perfect uses are ultralight groundsheets or waterproof bags and packs". I figured that because the raft will be inflated predominantly via a bag, the internal humidity within the raft will not be that great. Time will tell!

Another point to note is that this fabric is only coated with TPU on one side i.e. the nylon on the other side will be in direct contact with the water. I'm sure plenty of you already know this, but nylon absorbs water so this is something I may have to reconsider in the future. The real Alpackas have a polyurethane coating on this side which negates this problem. I've noted you can buy polyurethane spray cans from bunnings for woodwork, so I might trial a coating of this if I need to https://www.bunnings.com.au/british-paints-300g-satin-clear-polyurethane_p1400040. Other options might be a general outdoor waterproof coating, or a thin smear of silicone. We will wait and see...

Edit: I forgot to mention that when welding the fabric, the TPU coatings on your two pieces of fabric must be in contact with each other to create a secure bond. If you try welding the TPU coating straight onto the nylon you won't get a true weld (or it may look like it has, but is very weak).

Chezza wrote:Awesome! Thank you so much for the pictures and the detailed explanations.

No worries, Chezza. Let me know if you have any questions or queries! That website I linked originally is also a great resource and worth checking out if you are going to make one. I'll keep adding any extra hints/tips I pick up along the way.

FootTrack wrote:

Nuts wrote: From the videos I've seen of people modifying their rafts to self-bailers, I think it would be very easy to do with this design (e.g. with reference to Mark Oates' video https://vimeo.com/156952675, baffles could be easily bonded to the floor using the TPU-outside option explained on the diypackraft.com website).

Curiosity gets the best of me and seem to have ended up with a range of rafts. As far as self bailing, I really like Aire's design, just simply a sleeve with a removable inflatable floor (they attached the floor valve to the sleeve otherwise it could work with some sort of DIY sleeping mat perhaps).

As you say, not really necessary for slow water/ lightweight design.

Both Aire (Bakraft) and Feathercraft use Halkey-Roberts valves, they sit flush with the surface. Nice, positive locking, non- return system but a bit finicky to use and maintain.

I like your project, straight in at the deep end
Will indeed be fascinating to see it shaped and come together.

Awesome- this is great! Good on you for giving it a go. Looking forward to watching your progress...

Lizzy wrote:Awesome- this is great! Good on you for giving it a go. Looking forward to watching your progress...

Thanks Lizzy A lot of my projects make it into the "three-quarters finished" box but I'm pretty excited about this one so hopefully shouldn't have any issues completing it!

Nuts wrote:Curiosity gets the best of me and seem to have ended up with a range of rafts....Will indeed be fascinating to see it shaped and come together.

Thanks Nuts, I haven't heard much about Aire packrafts until now. Just searched the Halkey-Robert valves then, and they look very interesting. I'll have to read up on them - they might be a good option next time round.

I had another good session on the raft last night and now have all the curved seams done. Some odd photos from the last couple of nights are below.

Firstly, a word of warning! Always be thinking about where your fabric and iron are positioned when welding! This has happened to me a couple of times now and it's pretty annoying when you get a whiff of nylon and look down to find you've burnt (another!) hole in it. With mine, the tip of the iron gets hot but not enough to immediately burn through the fabric...it's the main shaft that comes out from the handle that you have to worry about. It is obviously much, much hotter and it instantly creates a hole. Tiredness and loss of concentration probably has a bit to blame here, but it is also easy to do when the fabric starts puckering up and coming off the table. Anyway, I bought some aquaseal this afternoon so I'll just have to go back and touch up these spots.

The next photo shows how the fabric is constituted; a nylon base with a thin, TPU coating on the other side.

This photo illustrates how I've been welding the curved seams over the riding helmet. As I mentioned previously, the TPU coatings need to be touching to create a strong bond hence why the strip is being run along the underneath side here.

Once I've tacked the strip along the length of the seam as in the previous photo, I flip it over to complete the weld on the other side. I get better visualisation of the strip edges this way and it prevents me from melting the TPU coating outside of the strip margin (which would lead to air/water leakages in the future).

This is the same seam with welding completed. Compared to the previous image you can probably see that the strip is less flappy and is bonded down more securely.

The right side of the packraft with all the curved seams done and the left side prior to being made the same. I know some of you are probably thinking a bed sheet could be made to look more packraft-like, but it was hard to keep stable sorry Once I've made them tubes, I'll try again


Finally, I weighed the valve and two sides of fabric last night and I was pretty blown away to find that all up they weigh just 325 g! If my rough calculations are correct that should mean that with a piece of fabric for the floor added, the raft should weigh under 500 g in total. I know this is horses-for-courses stuff, and that this raft would not hold up to same sort of abuse given to other rafts, but I'm still impressed at how light it will be!

Anyway, better get back to it!

This is like waiting for the next episode of your favourite TV show!
Really enjoying your build and thanks again for the detail and effort you have gone into documenting it

I am following with interest.

I'm not quite seeing it yet the wonders of technology eh !

Lizzy wrote:This is like waiting for the next episode of your favourite TV show!
Really enjoying your build and thanks again for the detail and effort you have gone into documenting it

No worries Lizzy I'm stoked that others are as excited about this as me, so it's a pleasure to share it with you guys. My partner is also overseas at the moment, so I guess there's an element of "taking my ear bashing elsewhere" to this thread as well

Nuts wrote:I'm not quite seeing it yet the wonders of technology eh !

What do you mean, Nuts? As in the photos aren't appearing or you think it more closely resembles a bed sheet?

Unfortunately, I didn't get as much done on the raft as I had planned over the weekend. However, one of the halves has now been welded into a tube so that was a small win I guess.

Before I started work on the tubes though, I decided to repair any holes/questionable bonds to the fabric. I wanted to address this before the inner surface became inaccessible, because repairs to the inside of the tubes will obviously be less prone to abrasion and repeat damage than what they would be on the outside. I also wanted to avoid having numerous patches and blotches of aquaseal on the outside which would be visually unattractive.

After a quick ride to the shops, I had my aquaseal and was ready to roll. There are two different types of aquaseal you can get; a fast (almost instantaneous) UV setting aquaseal, and a standard variety which has a longer cure time. I chose the standard variety, which has a set time of approximately 8-12 hrs (touch dry for me was after probably 30 minutes). I didn't want to have to rely on adequate sunlight to cure my bonds and the standard variety has a longer shelf life once opened, which suited me better.

There were four types of repairs I was on the look out for:

Holes outside the curved seam strip, which could be repaired simply by welding a square patch over it.

Holes on the curved seam strip which wouldn't allow a TPU patch to be welded to it. In these cases, I put aquaseal on a Nylon/TPU patch and glued it over the top of the hole.

Wrinkles/puckers to the seam strips which could allow air/water to pass through them. These were fixed by putting a dollop of aquaseal over the entrance.

Gaps between the fabric along curved seams. If my iron had made contact with the bonding strip below (likely), the TPU coating would be breached and could let in/out water or air. I identified these gaps by shining a light at the bond from the opposite side (like candling an egg). A smear of aquaseal along these lines reestablished the bond's seal.

Below is the seam above from its outer surface. It's much harder to pick the gaps by just looking at it from this side.

I used one 7g tube of aquaseal to repair both halves of the raft, which I thought was pretty good considering how liberal I was with it.

Finally, here are a couple of photos of the two halves of the raft having had all their curved seams bonded.



I won't discuss anything about the tube I just welded until tomorrow night. I want to get a couple of good photos (because it looks far more impressive than the ones above! ) and there is a bit to talk about with it (including a couple of lessons/nervous moments!).

FootTrack wrote:

Lizzy wrote:What do you mean, Nuts? As in the photos aren't appearing or you think it more closely resembles a bed sheet?

Pics are fine, it was looking a bit hard to picture coming together, getting it now.
CAD skills I don't have, i'd have hewn a mold from a log and had a pattern 2 yrs later : )
..so there's a bit of fascination.

PS. I use an old gas iron with a cutting tip. The tip is nice but the old iron isn't the most stable.
I had similar blowouts here and there, especially with light nylon and lighter weight cuben material. Using a metal edge (steel ruler) to follow on straights and bent around pins.. for curves, seemed to regulate the heat well, regulating the hot spots and slowing down the cut. You seem to have your method/speed for this worked out ok though.

Nuts wrote:Pics are fine, it was looking a bit hard to picture coming together, getting it now.
CAD skills I don't have, i'd have hewn a mold from a log and had a pattern 2 yrs later : )
..so there's a bit of fascination.

PS. I use an old gas iron with a cutting tip. The tip is nice but the old iron isn't the most stable.
I had similar blowouts here and there, especially with light nylon and lighter weight cuben material. Using a metal edge (steel ruler) to follow on straights and bent around pins.. for curves, seemed to regulate the heat well, regulating the hot spots and slowing down the cut. You seem to have your method/speed for this worked out ok though.

Ah yea, I understand you. Yea it's hard to get a sense of what it's like from a photo. When you have it in your hands it's very obviously a packraft. I think you'll get a kick out of my next set of shots - the fabric has now taken on a much more characteristic packraft shape!

I'm the same, I don't have any CAD skills either. I was lucky to be able to acquire the plans because I certainly wouldn't have started this project otherwise.

Interesting to hear about your old iron. My blowout problems so far have been mainly caused by the fabric crinkling up and bumping into the shaft of the iron when I'm not looking. Thankfully, the spade-like iron tip on the end doesn't get hot enough to burn holes in the fabric (having said that, I've been religiously taking some heat out of it by rubbing it on a cardboard strip prior to welding). I wouldn't go out and buy a temperature controlled iron for the sake of it, but I think there would be advantages in using one if it was already part of your inventory.

How much use have you given that mid that you made, Nuts? Are you happy with it/would you change anything?

It's a bit of an art with the iron You'd be fine with simpler shapes (like the mid) after this. Very similar skills in cutting and forming.. bar the joys of organising the tape so it doesn't stick to everything. Go for it

Mid is great, lots of little things i'd change. The shape has held up to a few solid nights weather here and there, the shape and the tapes, glues used- all good. Condensation is bad but that is expected (mine ended up like a tube tent with little side ventilation), I had a few nights with that one by rivers and it was soaked. I also made a few mistakes in finishing, hard to incorporate changes later in the building. Personally i'd consider side-opening, it takes some nimble moves to get in the end.

Hey guys

This update will cover what was involved in turning the fabric from a sheet, into a tube. I have also reinforced this tube since, but in the interest of time (and more photos!) I will leave that topic to a future post. Hopefully this won't be too boring a read - I've included more details in this post because this part was probably the most challenging of the project so far. There are also some potential hiccups not mentioned on the website that newcomers should be aware of. Anyway, enough chat!

I started out by making a template of the raft floor. I have found it more convenient having multiple templates for the different pieces, as opposed to one do-it-all template. The original plan had the floor marked out with a dotted line, but I made this a solid line for improved accuracy when cutting it out. I also labelled the front to avoid the devastation of finding out I had bonded the floor in reverse!

It's not shown in the next photo, but again, I pinned my fabric and template out with books before tracing on the floor margin. To determine where to place the template, I took a measurement from my plan using a curved seam as a landmark.

I used a red "Sharpie" permanent marker to trace the floor onto the fabric. I chose this over chalk for two reasons. Firstly, chalk on a seam surface has the potential to reduce bond strength come welding time. Secondly, this area will eventually be covered by another piece of fabric so permanently marking the fabric was not an issue.This line marked on the fabric becomes the back of the seam. Depending on how thick you have designed your seam to be, you need to draw on another line more centrally so that you can visualise the floor margin when welding down your tubes (your back seam will be invisible at this point). For reference, I have chosen a 4 cm tube-floor seam width on this raft.

Following this, I marked my seam width on the fabric which would be coming down to the floor. I marked this line with chalk due to the surface being nylon, and not TPU like before.

I then cut my curved seams to the edge of the chalk mark as seen below. This was so that I could visualise the back seam mark and position my fabric accordingly, prior to welding. It's worth taking your time at this point as a good first weld creates a solid foundation for the rest of the seam (do a poor one and it's all down hill from there as I discovered! )

Ready to weld. Again, pinning out the fabric is imperative!

The next photo shows one of the mistakes I made (and which I now do differently). Avoid cutting out the corner and trying to make it look great, before bonding the seams on either side of it. Once you've got the seams on either side bonded down, the joint becomes much easier to manipulate and can be made near perfect. If you do otherwise though, and make a misjudgment on how much fabric needs to be cut away (easily done when the fabric is non-welded and mobile), you risk affecting the alignment of the next seam and the joint itself will likely look second rate. [Note: I made a small mistake here regarding how I originally welded the strip down to the edge of the fabric on my curved seams. I will elaborate on this more in my next post.]

The second and probably most important lesson I learnt, regarded the order in which the seams should be welded. After welding the long, straight seam (1) I found it easiest to weld the midline seams (2), followed by the seams in between them (3). I had a few stressful moments trying to bond seam (3) immediately after (1), and ended up having to take the seam apart and redoing it again with aquaseal. I was feeling well out of my depth at this point and was starting to wonder why I hadn't just repaired the puncture in my old pool toy! Luckily it all went smoothly after changing the order though, and I bonded the rest of the tube without any issues. These seams are much more difficult to bond than any done up until now, as they are curved, have overhang from tube above, and involve large lengths of fabric. Welding them is certainly achievable but requires patience and attention to detail.

Below is the long, straight seam (1) after being welded down. The number of air bubbles that appear under the fabric can be reduced by welding out from the centre line. Whilst welding I also had to regularly re-chalk my margins as they could be easily brushed off with all the handling.

Finally, once the seams were complete I went back and put a blob of aquaseal in each of the corner joints as the apex was difficult to access and I was skeptical as to how waterproof they were.

I'll leave you with these shots of the tube packed with clothes/blankets etc., showing what it will pretty much look like when finished!

Well done! It's certainly beginning to take shape now.
I am also seeing why Alpacka and co are the price they are!!!!

I'm just loving this project FootTrack, amazing


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Great work! This looks like one of those really satisfying projects where you just jump in and start and end up with something amazing that you can scarcely believe you've made.

Man, that's definite progress. We'll see this thing finished for sure! I'd get to a certain point and leave it for a bit, which would turn into months, and it'd then never get finished!
Best thing is, everything you've learnt on this one will make the next one so much easier and quicker