site  contact  subhomenews

Sewing neophyte slowly learning

June 14, 2021 — BarryK

What has plagued my sewing so far, is thread getting caught up in the bobbin area, and a rats nest of threads on the underside of the fabric.

Today I watched a couple of videos that have resulted in significant improvement:

Singer 4411 Heavy Duty 12 Tension Test:

Singer 4411 Heavy Duty 13 Holding Threads When Starting to Sew:

Following the instructions, I found that the tension setting is the culprit. I had it set just above "4". Changing it to just below "4" did the trick.

Incidentally, I am now using Guterman Extra Strong thread from Spotlight:

No particular reason for changing from the lighter thread, except that it looks good.

And as before, a sharp/microtex 80/12 needle:

Another problem occurs when do a back-stitch at end of a line of sewing. The Singer 4411 has a lever, press that and then the foot lever, and sewing will go back. It is normal practice to do this at start and end of a line, however for me it results in messed up threads on the underneath of the fabric.

The hint I got from watching the videos, is, when get to end of a line, wind the wheel at right-side of sewing machine counter-clockwise, until the needle is up and the metal part comes up out of the top of the sewing machine, to it's highest level. That completes a sewing cycle. Then hold down the reverse-lever and sew backwards.

Not quite sure about that last paragraph, have to experiment some more.

EDIT 2021-06-15:
I have gone back to using standard Guterman thread from Spotlight, which is, I think, called "sew all" thread in some other stores.

Reason is, I cannot stop thread bunching underneath the fabric when sewing webbing onto the fabric. I messed around with tension setting, tried both walking foot and standard foot, to no avail.

Back on the "sew all" thread, with tension setting just on "4", it is working reasonably well. Still not perfect, sometimes get small loops at start of a line of sewing, and when reversing. But much better than the mess I was getting with the "extra strong" thread.

One of the things that annoys me about Spotlight, is they often give inadequate specifications. See the above link. I determined from reading elsewhere what kind of thread it actually is. 

EDIT 2021-06-16:
I mentioned above about finishing sewing with the lever sticking above the sewing machine. This video shows what I mean:

"Singer 4411 Heavy Duty 20 Take Up Lever in the Highest Position"

...she calls it the "takeup lever".

She advises to do it at the end of a line, before lifting the foot and removing the fabric.

But see in that video, she got to end of line, held down the backstitch lever momentarily and did a quick back-stitch. Didn't bother with getting that takeup-lever at max height.

So I still have the problem of some looping underneath the fabric when back-stitch. Forum member williwaw has suggested that I might need to adjust the bobbin tension. Will read up on that.

EDIT 2021-06-16:
Hey, she -- her name is Sara -- does have a video explicitly on back-stitching:

"Singer 4411 Heavy Duty 16 Reverse"

Interesting, she sews in reverse at the beginning. And does it real fast, like she doesn't even take her foot off the floor pedal.    

Tags: light

Catenary cut for tarp ridgeline

June 09, 2021 — BarryK

After constructing the TH1P tarp Mark-1 and erecting in my lounge room, then eye-balling it, I realised that it would be better if the ridgeline is joined in a catenary-cut. Previous post, showing photos erected in lounge room:

It is not apparent from those photos, but the fabric either side of the ridgeline is loose, not taut. even though I pulled the cords fairly firmly at each end. The problem is, the ridgeline is never going to be a straight line, no matter how firmly you attempt to tie each end. It will sag.

This photo shows the sag in a straight-cut ridgeline. OK, it is a bit exaggerated, because the ends have not been pulled firmly, but the shadow does show you the effect of the sag:


This sloppiness can be mitigated by having extra tie-outs on the sides of the tarp, but I would prefer not to have more stakes to hammer in.

There is a fix for this problem, to join the ridgeline in a curved shape, so when erected, the fabric either side of the ridgeline will be taut. This photo shows a tent which has such a curve:

img2 can see, a reasonably firm tension applied each end, the ridgeline has a sag, but the fabric each side is taut.

My apologies to whoever posted the above photos, for not acknowledging you. I downloaded them and don't recall the URLs. Ah ha, found one URL, but he also has "borrowed" the photo from somewhere else.

The curve shape is known as a "catenary". The Wikipedia defines a catenary as:

A catenary is the curve that an idealized hanging chain or cable assumes under its own weight when supported only at its ends.

So, it would be good to join the two halves of the tarp so that the ridgeline has this natural hanging shape. As I have already created a straight ridgeline, I decided to modify it to be a catenary.

Firstly, I need a formula for calculating the points along the catenary. Fortunately, 'XTrekker' has done it: can run the formula online, or download the Excel spreadsheet  -- which runs great in LibreOffice.

I have uploaded the Excel spreadsheet here.

Note, XTrekker's formula is for both ends of the tarp to be at the same height. My tarp is lower at the foot-end, but I don't think it matters if the cut is not to an exact catenary mathematical formula.

Back in an early post of these tarp construction instructions, I gave the dimensions of each side of the tarp, and the ridgeline was 222.2cm. After folding the hems, the final ridgeline length on my tarp is 215cm.

But the big question, how much "sag" to put into that formula? After a bit of reading other people's experiences of a minimal catenary, I chose 4cm. Tabulating the results from the spreadsheet:

Offset "b"
0 (centre)
107 (end)

I have modified my tarp, by cutting along the ridgeline, then re-glueing.

For someone constructing the tarp from scratch and wanting the catenary curve on the ridgeline, I would like to theorize on a couple of ways it can be done. Let's call them "method-1" and "method-2"....

Method-1: variable overlap

This sketch explains theoretically how I think it could be done:


The top sketch shows the two tarp ridgelines placed together, and the red dashed line is the pencilled catenary shape. There has to be some overlap at the ends, named "a", and in the centre there will be an overlap of "a" + "b", where "b" is from the above table.

One thing that I think you will need to be careful about, is not just to pull #2 side up to the pencil line, as the ridgeline will be slightly wonky. #1 and #2 edges need to be pulled equally. I think that a way to achieve a nice non-wonky join, is to do what I suggest in the bottom sketch.

I have indicated a sequence, 1, 2, 3, but you might find it better to do 2 first. That is, anchor each end firmly with weights, then pull the two edges so that they overlap and follow the pencil line. Then put in pins to hold the overlap in place.

Then step-3, glue. Tarp #2 will be sitting on top of #1, and you can glue it down. Usual procedure: dribble a line of silicone adhesive, then run your finger along to spread it, then press down. The only thing to be concerned about is that the spread of glue as you run your finger down, reaches the edge, so edge #2 is glued down all the way along.

Take out the pins, leave overnight. Next day, flip over and glue the other edge.  It is then wise to leave for several days, to fully cure.

Method-1 is wasteful of fabric and glue, and the tarp will be unnecessarily heavy, as the "b" value gets bigger. Plus, I am not sure how the ridgeline will hang with a large centre overlap.

I came up with that 4cm sag figure from reading forum posts, but those people were using method-2. So, "b" should be doubled for method-1, but 8cm fabric overlap is, I think, not the way to go. I am describing method-1 in this blog post, for consideration if you only want a tiny sag value.

The alternative is the traditional way, cut a catenary shape on the ridgeline edges of both tarps, and then join them with a constant overlap the entire length. This is Method-2...

Method-2: Catenary cut

Another sketch to show this:


With this method, you mark catenary lines on both edges, then cut. This is shown by the pink dashed lines. If you used a "b" value of 4cm, as per the above table, then you are going to get twice the catenary effect than for method-1.

On side #1, mark another line for the overlap. I suggest the orange dashed line to be 3cm from the pink dashed line.

To glue the two sides, I think that you could still use the pins. So you would pull side #2 over side #1, pull each end and put weights, then pin, then glue.

Leave overnight, then flip over and glue the other edge.

I used method-2 on my tarp, and used pins. To make it easier to insert the pins, I hung the two tarp-sides near vertically, using a plank. The plank is dressed pine, 184x19x2400mm. Use a large crocodile clip at one end, to hold the two pieces of tarp together, with 3cm overlap, onto the end of the board. At the bottom end, you could use another crocodile clip to hold the tarp pieces together, again 3cm overlap.

Haven't got a photo of that, but it should be easy enough to visualize. That made it very easy to insert the pins.

I then laid it horizontal and glued. I left the pins in, but that is OK, next day flipped the tarp over and glued the other flap.

I had removed the tie-outs at each end of the tarp. Need to reconstruct those, then will take a photo of the erected tarp, and will update the tarp construction details here:

This time, will use some heavier-duty webbing for the ridgeline tie-outs.

EDIT: TH1P tarp mark-1 with catenary-cut

I cut along the ridgeline, cut the catenary curves, re-glued, sewed new webbing tie-outs. Unfortunately, all this messing around has resulted in a lot more glue and some extra reinforcing bumping the weight from 178g to 218g, a jump of 40g. That is unnecessary extra weight, would have been less if had done the catenary-cut from the start.

Here is a photo:


I am really not convinced that the catenary-cut is worth the effort. Yes, it does take up some of the slackness along the ridgeline. The tautness will also have an advantage when wind hits the side of the tarp, it will more readily flow over the tarp, instead of trying to push it over. Some people cut even deeper catenary, but then they are going to be loosing more height inside.

A straight-cut is probably preferable if you want to erect the tarp in other ways, not just as a V ridgeline.

For the tie-outs on the ridgeline, I have gone for a thicker webbing. This, 12mm wide by about 1mm thick: is only available in black.       

Tags: light

Bottom tie-outs and tarp completed

June 05, 2021 — BarryK

Here is the previous post, in this "TreeHugger 1P tarp Mark-1" project, making the ridgeline tie-outs:

Today I sewed on the tie-outs along the hems. That is, the four corners and the middle of the sides.

I used the same webbing as before, nylon, just 10mm wide and 0.5mm thick:

Cut these pieces, 16mm long, folded over about 35mm and sewn, with rubber o-rings, and one of them has a hook. The one with the hook is folded over a bit more so that the hook is the same distance from the tarp as the o-rings:


The length of this webbing is a matter of personal preference, how high you want the tarp hem off the ground, and of course longer webbing will make the tarp wider when erected.

Note, when I cut the nylon webbing, I also use a flame to cauterize the ends. Important, otherwise the ends can unravel.

The o-rings are silicone rubber, 25mm OD, 4mm thick. They feel strong enough, however for future projects I intend to use o-rings made with EPDM rubber, as it is stronger than silicone rubber. Note also that EPDM is UV resistant. A cheaper rubber is NBR, and this is not UV resistant. This is what I have on order, 25mm OD, 4mm thick:

The plastic hook in the above photo is a bit bigger than I wanted, so I ordered a smaller size. These are 3.6cm overall length, just what is needed:

They arrived after the initial writing of this blog post, and I swapped for the smaller hook. The EPDM o-rings also arrived, but will keep the silicone rubber ones on the tie-outs -- the EPDM ones can be for mark-2 tarp.

Sewed the tie-outs on, with my newbie wonky sewing, and erected the tent in my lounge room:


The wooden frame is my "dressmaker's dummy", to make it easier to construct the inner-tent while inside the house.

The tie-out with the hook is front-right, as the tarp is intended to become a step-in and step-out tent, with zipper entry to the inner tent on the side.

Those o-rings are intended to go over stakes, and in the case of the hook, it will hook onto an o-ring. That is a detail that will become apparent when the inner components of the tent are constructed. For now, we only have the "stage 1" of the tarp, but still, you can see how the hook can be unhooked from the o-ring and folded over the ridgeline:


Actually, even at this stage, the side flap is useful. If the high-end was tied to a tree trunk, the pole not used, the side flap is a convenient way to get in and out.

Here is a rear view:


Now for the really interesting bit, what this tarp weighs. Wait for it...

Weight of tarp: 178g

Or, in Imperial measurements, 6.3 ounces. That is good.

What is planned next, is baffles for front and maybe on the low-end. The baffles are intended to facilitate exact spacing for the stakes, and to hold the o-rings firmly at ground-level -- so they will be less likely to be pulled up when wind blows on the tarp.

Planned erection procedure is you would stake out the tarp, with 4 stakes, then tie up the ends, with or without poles. I plan to use this without a high-end pole, as then the high-end ridgeline tie-out can be pulled up and tied to a tree, no need to have tension adjusters on the ground-level stake tie-outs. Of course, if you have a trekking pole, the length can be adjusted, so again, no tensioners required at the stake tie-outs.

The same principle holds for the low-end, but I will probably use the pole, as it might be difficult to locate a branch to tie to. Well, could use a stick, maybe with v-notch to run the cord over.

The front and rear baffles will also offer rain protection, and will have openings for ventilation.

These are future plans, but the tarp as constructed so far is quite useful. I cannot tell you how sturdy it is in windy conditions, as so far it hasn't been out of the house.   

Tags: light

Tarp ridgeline tie-outs

May 30, 2021 — BarryK

Continuing the "Mark 1" tarp construction project, this is the previous post:

So far, the tarp has been constructed by glueing, no sewing, but now, I have sewed the webbing onto each end of the ridgeline. The webbing I used is this:

With a cord tensioner:

I am going for lightest possible weight, but uncertain if have taken it too far with this webbing. It is nylon, 10mm wide and only 0.5mm thick. Apart from nylon having limited UV resistance, it is very thin. Might be better described as ribbon, than webbing, but it seems strong enough. If it breaks, I suppose can sew on something else later.

I have a Singer 4411 sewing machine. Set it to zig-zag stitching, width "1" and length "3". Using standard Guterman polyester thread from Spotlight -- I think this is known as "sew all" thread at some stores -- Spotlight also have "extra strong" but didn't use that. Set the tension to just above "4". Using a walking foot.

One more thing, used a sharp needle, size 80/12:

...apparently, the standard needle that comes with the sewing machine, has a slightly rounded point, designed to push-aside threads, which is (apparently) not the best for sewing ripstop.

The reason to stitch zig-zag is that polyester thread is far less stretchy than nylon. This means that a straight thread may break when the tarp ridgeline is pulled very tight. At least, that is advice I got off the Internet.

The original plan was to sew a nylon washer underneath, for the support-pole to slot into. I did that, but it doesn't look sufficiently robust:


Scrap that idea. The carbon-fibre pole has a rubber end-cap, so there is some spread, but what is needed is something to keep the pole in place. I want the pole to be right under the webbing.

Found a length of 25mm nylon webbing, cut two pieces, clamped them together, then used a soldering iron to make a hole:


Good, created a hole into which the pole end-cap can be inserted, with side-walls high enough to keep the pole in place. Then glued it to the tarp:


Looks good. Could have gone even further, with 3 layers of webbing.

Note, glued a tiny piece of ripstop underneath, so the pole is not rubbing directly on the webbing.

Note, if that sewing looks a bit wonky, it is. I'm a sewing newby, was experimenting with different zig-zag widths etc., while doing it. Yes, did try on some scrap fabric first, but still had to play with settings while doing the actual job.

Will do the same for the other end. Then will do the tie-outs on the bottom of the tarp. A bit of delay there, as ordered plastic hooks, that go onto end of webbing or cord, and they haven't arrived.

Some other items ordered from Aliexpress also haven't arrived. Then I made a discovery. Although I had chosen "Aliexpress Standard Shipping" when ordering, these non-arrived items were shipped by China Post -- which is considerably slower to Australia. The vendors took the extra money that I paid, and then posted by the cheapest means.

I have complained to two of them, asking for a refund of the difference. Anyway, I found another vendor of those plastic hooks on Amazon, placed an order.

EDIT 2021-05-31:
The above picture is for the ridgeline at the low-end of the tarp. The high-end is a different story, as the walls form an acute angle. The "cup" that will hold the pole will have to be as narrow as possible. I oriented along the ridgeline and also trimmed the width a bit with scissors:

img5 is 4 layers, 3 of them form the "socket" into which the pole will be inserted.

Still concerned that this is too wide. Maybe also too fragile. Anyway, will see how it performs when in use.

Though, I don't intend to use a pole at the high-end, so the fragility might just be an academic issue. Most interested in erecting it in "tree hugger" mode.

Ideally, want the "socket" to be no wider then the webbing. An idea is a plastic screw-on top off something -- like the screw-top on a tube of toothpaste, but it would have to be wider. Then drill tiny holes in the base, so that it can be sewed onto the tarp. Or even glued to the webbing with epoxy resign. Maybe will do that for tarp "Mark 2"! 

EDIT 2021-05-31:
Thinking about it some more, a narrow "socket" for the high-end could be achieved by these silicone end-caps:

I already have some with 7.7mm ID, 11mm OD, which would be just right. As they are silicone, they can be bonded strongly to the webbing. A bit of reinforcing around the end-cap could enhance the bond integrity. Maybe even some epoxy resin in the bottom, to spread the force. Just making a note of this alternative, a possibility for the "Mark 2" tarp.

EDIT 2021-05-31:
Hey, why not? I cut the 7.7mm ID silicone end-cap a bit shorter, and glued it into the hole previously created:


Now, just insert the metal pointy-end of my carbon-fibre pole (or a trekking pole), and we are good to go. The ridgeline width is still a concern, but we shall see once it is up and in use. The CF pole I am referring to, is this one, purchased awhile ago (125cm, 5-segment):


Actually, I have two CF poles, see report here, but the other one is not suitable for this tarp, as shorter: 

EDIT 2021-07-04:
I am now favouring a simpler method for the "sockets" in which the poles are inserted. Just glue the silicone end-cap onto the webbing. That's it, nothing else. See details here:


Tags: light

Constructing short pole for tarp

May 27, 2021 — BarryK

Continuing construction of an ultralight tarp, this is the previous post:

The tarp has a ridgeline, with a high head-end and a low tail-end. The head-end can be tied directly to a tree-trunk, branch or can sit on a trekking-pole or a 125.5cm carbon-fibre pole.

The pole for the tail-end is to be 48.5cm, and I want  it foldable, no longer than 25cm so as to be able to lay flat in my backpack or lumbar pack.

The tarp is intended to have in inner mesh tent permanently sewn in, and the tail-end pole will also be sewn-in. The 2 pieces of the tail-end pole could have bungee cord to keep them together -- that is the usual method -- however, being sewn into the tent, think will be able to avoid a bungee cord.

I have carbon fibre tube, 4x6mm (IDxOD) and 6x8mm (IDxOD), the latter to be used as the joining sleeve. Here is a picture:


Those 4x6 tubes are 24.8cm long each (without the end-caps), and I cut 3cm length of the 6x8 for the joining-sleeve. There are rubber end-caps, that add a couple of millimeters on each end.

When pulled apart, the two pieces will fold to be the same length, close to 25cm. To achieve this, one of the 4x6 poles had to be cut short, to 23.5cm (including the end-cap) -- this is the piece that will have the 3cm sleeve glued onto it -- inserted 1.5cm onto the 4x6 pole, thus giving a total length of 25cm.

For the 23.5cm pole, I wrapped electrical tape around it, then sandpapered the surface so that the glue will adhere better. The photo shows this, and in the middle is the 1.5cm piece that I cut off the pole:


I discussed on the Aussie bushwalking forum what glue to use:

...decided on epoxy adhesive. It turned out well.

Here is where I bought 4x6 and 6x8 carbon fibre tube:

The silicone rubber end caps:

Just a little detail, the 4x6 does fit inside the 6x8 tube, but is a tight fit, and I used some 4x6 that had purchased earlier from another vendor on Aliexpress (here), as it is a slightly looser fit inside the 6x8 sleeve.

The epoxy adhesive is a very cheap brand from Bunnings:

Getting closer to the weekend, when I will have waited long enough for the silicone sealant to cure, and will be able to sew the tie-outs.  

Tags: light

Tarp glueing reinforcing

May 23, 2021 — BarryK

Continuing with contructing TreeHugger 1P Mark-1 tarp. Here is the previous post:

Reinforcing is to be at the tie-out points. I used the same 10D silnylon, and two plates from the kitchen to cut circles. I cut out two sets of circles, 15.5cm and 21cm diameter -- nothing special about those sizes, they were what I had in the kitchen that seemed about the right size.

Here is a sketch showing where the reinforcing is to be applied:


"A" is glued on top of "B" on the ridgeline, for extra strength.

Here is one of the bottom corners:


The reinforcing on the ridgeline were larger pieces, more of a challenge to glue down. You can see the ripples, somewhat less than a perfect job:


One good thing: it will be very easy to sew. If I decide to reinforce with some sewing later on, won't have to grapple with two pieces of thin slippery fabric trying to go off on every direction.

I was reading a post from someone, can't recall the link, who glues-on reinforcing, and he said to wait several days before sewing. The reason is, the silicone will cure quickly at the edges, but underneath the two layers of silnylon, it will take many days to cure. He said, if you do it too soon, it will gunk up your sewing machine -- especially around the bobbin.

Next, I will sew on the webbing tie-outs. But, oh no, I will have to wait several days! Hmmm, maybe work on EasyOS or something.

Now the really interesting bit: I have been weighing this tarp as construction progressed, and the weight is now 158g. This is so good. I estimate the webbing and a bit of hardware, such as cord-tensioners, will add another 15g, bringing the estimated total up to 173g. That is just the basic tarp, but I do plan to add more features, such as rain-baffles on each end, plus an inner mesh tent, but I do now expect the total tent weight to be well under my original goal of around 500g.     

Tags: light

Tarp glueing hems and ridgeline

May 21, 2021 — BarryK

Continuing the project constructing TreeHugger 1P mark-1 tarp, a simpler design than originally conceived. Previous post:

I decided to glue the entire tarp, and only sew the tie-out webbing. Really want to find out if an almost-totally glued tarp will be strong enough. Of course, it very much depends on the weather conditions in which it is going to be used. I am in Western Australia, Mediterranean climate, but there will be some high winds on the South Coast. Unlikely to ever use it in "gale force" winds.

The tarp consists of two pieces, that will be glued together at the ridgeline. This stage of the project started with getting together support items:


The idea of the roller is to run it over the seam, to ensure both surfaces are pressed into the adhesive. I purchased this 30mm Seam Roller from Bunnings:

The Parfix All Purpose Silicone Sealant is also from Bunnings, a small 40g tube:

I reckoned that it would be easier to handle a small tube, rather than a large 300g tube with dispenser.

The roller is in a cup with mineral turpentine, the idea being to clean any silicone off it. The gloves are vinyl disposable.

The sides and bottoms of the tarp are just simple folded-over hems. What I did was lay the fabric over a dressed-pine plank, with some weights to keep it in place:


And used the marking pencil to draw two lines, 1.5cm apart:


...oh, you can see my awful cutting of the edge! That was a particularly bad spot, lack of concentration. Probably a roller-cutter would do a straight line, or a soldering iron.

What is to happen here, is first adhesive is spread between the two lines, then the edge is folded over. Seems simple enough in theory, and in practice wasn't that difficult.

I am left-handed, so it seemed most natural for me to start from the right side, and use the left hand to apply the adhesive, then spread it with a thumb or finger of the left hand. I dribbled a very thin line of adhesive between the two lines, then with one sweep of the thumb, held sideways, spread the adhesive into a thin film, hopefully filling the entire space between the two lines.

I did it a section at a time, using the newspaper edges as convenient stopping-points.

This spreading operation has to be done in one go. Going back and trying to spread it around can end up in a mess. As I was very miserly with applying the adhesive, it didn't always spread out to 1.5cm. But for the hem, I think that is non-critical.

I waited several hours between doing each hem, then finally got to doing the ridgeline...


I first spread cling-wrap over the wood plank. Reason is, cling-wrap is made with polyethylene, which silicone does not stick to. I have cheap Woolworths brand cling-wrap, and it doesn't say on the packet what it is made with, but I tested, and confirmed silicone sealant doesn't stick.

I marked a line 3cm from the edge, then lay the other ridgeline on top. So, 3cm overlap.

Now for the tricky bit, how to glue this without the two pieces moving all over the place...

With the two pieces of fabric in place, I put a lot more weights here and there, so that if the edge of the top fabric is lifted, when let go, it will naturally fall back into the same place.

A problem with silnylon is that it is stretchy, particularly this thin stuff. So you can't pull it. It really has to be as much as possible placed so that the upper edge will just fall down in the correct place. You can lower it with some encouragement to meet the edge with the chalk-line, but do not pull the fabric longitudinally -- we do not want the top piece stretched when the bottom piece isn't.

Due to the 3cm width, I applied the adhesive in a zigzag pattern, then used the side of my index finger (finger closest to the thumb) to spread it. As with the hem, I did a small section at a time.

The ridgeline turned out OK, except that I was too miserly in administering the adhesive. Wasn't quite getting 3cm spread in some places. I measured afterward, only use 4g adhesive in the ridgeline, much less than anticipated. What I will do later on. is go back over the edges that are not fully stuck down, apply more adhesive.

Here is what the ridgeline looks like:


Now for measuring the weight...

The two pieces of silnylon weigh 128g. After glueing the hems and ridgeline, total weight is 144g. Oh man, that is light!

What is going to be very interesting is how much weight the tie-outs will add. Plus a bit of remedial glueing on the ridgeline -- but that will probably only be a few grams.

A note for those who haven't been following my "traveling light" posts, I am trying to reduce the weight carried in my Mountainsmith Daylight lumbar pack, from 4.5kg to 3.5kg (including weight of the lumbar pack). So the tarp, and planned inner mesh tent, are mostly being designed for light weight and compactness, rather than for durability.    

Tags: light

TH1P mark-1 simple tarp

May 18, 2021 — BarryK

I have posted about interesting ideas for a tent, that I named "TreeHugger 1P":

However, as I am a neophyte at tent construction, and indeed anything to do with sewing and fabrics, I decided that baby-steps are in order...

So have modified the outer skin of the tent to not have the spreader-pole, and just be a simple tarpaulin. I made the foot-end a bit higher -- want poles that fold to no more than 25cm long, but can have two poles at the foot-end, that lock together, achieving about 49cm length.

This simple tarp can still be tied up as a "tree hugger", and later could add an inner mesh tent. Just want to create this tarp first, to learn how to do it.

So, from SolveSpace, figured out the required dimensions of the tarp. Here they are, and sequence of marking the fabric shown in green:


I marked it with a clay fabric pencil, this one, which marks OK on the silicone surface:

Used normal general-purpose scissors, new and sharp, to cut out. It isn't easy, this stuff is so slippery, can't cut very straight. It doesn't have to be a perfect straight line, as all edges will be folded.

I bought new scissors, as they have to be sharp. Scissors get blunted when used to cut paper. These ones:

The fabric is 10D silnylon, silicone-coated on both sides. In fact, it is impregnated right through with silicone. So it is not only incredibly thin, but also incredibly slippery. I wasn't able to source it in Australia, so bought it from these guys (7 metres):

I then used the first one as a template for the second:


Marked out with fabric pencil and cut the second. Very difficult, as my lounge room is too small. A large floor area is required, so can walk all around the sides.

Next step will probably be to sew or glue the side and bottom hems. After that, join the two pieces together along the ridgeline. Note, the reason that the ridgeline has to be cut along the side of the fabric, is that ripstop fabric is more stretchy when pulled diagonally. We want minimum stretch along the ridgeline.  

Tags: light