Thursday, May 31, 2012

Tent Trials- Remarks

So far this tent has definitely been a learning experience. I have come to the conclusion that the most feasible internal structure would be a spoke hub due to the sagging that occurs with heavy canvas. Most period artwork and surviving artwork also supports this theory. I also have come to appreciate the time and considerable cost it would take to make a tent in a medieval setting.

So far it has taken us at least 50 hours of labor to put together this tent. This time does not include the time spent planning, researching, or accruing materials. This is also using modern tools and machinery. We still have to paint the walls, finish the door ties, create the permanent crow's feet, and the hub and spokes.

As for the costs the canvas tarps cost us about $300. We spent approximately $150 on other materials. Including, the frame, ropes, paint, waterproofing, thread and notions, hardware, and heavy duty ground covers. We could have saved some money on the frame which is a bit overbuilt (4x4 hem fir poles and fancy brackets). Also the paint and the ground covers cost $75 just by themselves, and were not necessary, but we wanted to stay dry and give a medieval feel to the tent.

Some things I will continue to do is create a roof lining, and possibly the walls also, since the canvas has some minor flaws to it. I eventually want to get some uposltry fabric to attach to the ground cloth, to give a more medieval feel. I will be painting the walls. We will be creating a spoke hub.

Wednesday, May 30, 2012

Tent Trials- We have a tent, well sort of...

So I finally got the roof up on the poles, since we were waiting for me to be done painting and to water proof it. I also got the walls mostly sewn, I just need a couple of straps to close the doors. The guy lines that are attached to the shoulder are just temporary, until I get the real rope tied into the crows feet. I have not yet painted the walls, nor are they staked in the right place in the picture. There is a big reason for this.....

The guy lines do not keep the roof tight enough to prevent sagging, which means the shoulder is lower, which means the walls do not line up right if pulled all the way out (right side of tent), or they sag if they are in the right place (left side of tent). I do not know if it because the roof is to heavy for the temporary lines I have up or not. I suspect it is the not.

There are a couple of ways It could be fixed, we could raise the center pole 7 to 8 inches, and then the walls would hang right, but the roof would still sag. We could rig up an outer ring to stiffen the shoulder, which would prevent sagging of the roof between the guy lines, but might not keep the shoulder at the height needed. Having perimeter poles would make all the bell space unusable. If I had more canvas I could rip out all the seams, and add more, so the bells would line up, but I do not have any extra. So that leaves retrofitting a hub and spoke system, that would solve both problems of sagging shoulder and wall fitting issues.

Unfortunately I do not think that we will have time to fit it before the event this weekend.... We will have see what tomorrow brings... Maybe I will even get to paint the walls.

Monday, May 28, 2012

Tent paint musings

I had a lot of time to think about painted tents while I was paining my roof. Most painting of tents have the seams painted at least and many of them have arches also. Paint has some interesting properties. For one, paint makes things stiffer. It also makes canvas shrink. It would be odd to only have the seams painted and the rest of the tent floppy.

If the whole tent was painted in a gesso it would stiffen up and shrink the whole tent. The shrinkage would be uneven, because the stiffer seams would not quite shrink as much. This would help account for the uplift seen inbetween the painted seams at the bottom of the tents. If the whole tent was painted it would make for a stronger tent. The stiffness would help shed both wind and water. The paint also help seal any seams, prevents fraying, and makes the fabric less susecptable to puntures and tears. It also makes the surface easier to paint with color and achive fine lines and intricate patterns, which would be harder on canvas that absorbs liquids.... paint seaps on raw canvas.

If just the seams are painted they are reinforced, but what if the arches are not just decorative?? What if the arches are structural? Paint stiffens up the arches and the seams, spreading pressure and tension.

Tent trials- setbacks and progress

So I have been very busy with the tent. I have finished one curtain wall section, but unfortunately I have to wait until tomorrow to sew the other one. Amazingly I have only broke two sewing machine needles. I had bought 3 new heavy duty needles before I started this sewing project, but one rolled away and can't be found, I broke one, and the third must be flawed, because every 20 stitches or so, it slices through the thread. Saturday morning the needle I broke was towards the end of the wall curtain so I suffered thru the last three straps and a short hem with the flawed needle, but there is no way I will do that for an entire wall curtain. So I have to wait until a trip to town to get new needles.

Also when we were in town getting rope for the guy lines we forgot to include the ropes supporting the peaks, so we need to get more rope on our trip to town.
 On the positive side, we have the frame finished. My DH used his tools to taper the 4x4 posts, sand all the wood, drill holes, create a base, bend and sharpen metal stakes, and created the guy lines for the peak. Then he put it all together with some fancy shelf brackets. Here is a pic of it erected in our yard.

Since I was unable to sew the other curtain wall, I have been busy with other tent related things. I have all the toggles cut for the walls to attach to the roof. I also have the roof entirely painted. I used exterior latex paint, thinned down to 1 part paint 2 parts water. The reason I thinned down the paint is because I want the paint to be soaked up by the canvas, not just a layer on top that can flake off.

Painting tips, tricks and errors
1) Paint thinned down this much is messy, It will run slighty, and the color will not be completly even. Do not have someone help you who does not know how to work with thinner paints. If you want crisp lines, soild colors, or something less delicate, do not water it down so much. Personaly I like character, plus I would rather not have the paint crack or peel off.

2) Do not use crayon to mark you design on your canvas..... the wax will show thru, doesn't matter what color.

3) Go slow and be carefull paint drips get soaked into the canvas and can't be removed, and can be hard to cover up.

I still have not been able to set up the roof on the poles, due to the lack of rope, but tommorow after I water seal it I am hoping to get it up.


Thursday, May 24, 2012

Tent Trials - The Roof

So I have finished sewing the roof. 
I tried to set it up outside to see how well it lays out, but alas the weather was not cooperative. 30 to 40 mph winds are not condusive to setting up a tent roof for the first time, nor are tornado watches and thunderstorms. But here is a pic of the thing folded in half. As you can see it takes up almost my whole kitchen!! I will eventually get one of it set up.

So to start I used flat felled seams throughout. Here is a link explaining these seams. As I was sewing I discovered that my 1 1/2'' seam allowances were a bit to generous, so my finished roof panels are all about an inch bigger than I was planing, but since my walls have the same seam allowance, they will also be a bit bigger. This gives all my tent dimensions a few extra inches. 

 This next pic is of the welded ring I am using at the interior peaks of my roof.  There are three reinforcing straps, which attach to six of the seams, taking the stress off of the seams and fabric.

This is a pic of my exterior edge. You can see the small straps sewn onto the 2" lip. This is where the crow's feet guy lines will attach. The lip has several lines of stitching ran through it all the way around, and sewn into on the interior it are straps which the walls will attach to. The interior and exterior straps line up to prevent sagging. Below that the rain guard will hang down about six inches.
I had noticed when I was attempting to set up the roof outside, that the canvas has a few minor flaws to it. I am not sure if they will be able to be 100% waterproofed by the sealant. So I will be making a simpler roof lining out of some of the huge piles of cotton I was given. There are surviving tents, such as the Carlos V tent, that have a second roof, that hangs a couple inches inside the exterior roof. This could have been to help with the misting that can occur with natural fabrics in wet conditions. I can use the same pattern pieces I have and just eliminate the seam allowances.

Sewing this has given me a very profound admiration for the people who created these tents without the use of machines. Even with the machine, this roof has taken me over 10 hours of just sewing!!! I cannot fathom how long it must have taken to do this by hand.  

Wednesday, May 23, 2012

Tent Trials - Planning and drafting

So it turns out that my sewing machine can handle several layers of the canvas. It also turns out that I had two free weeks before the next camping event. So guess what I have been doing????

Gardening. Alright that is what I should be doing, but I am also sewing my tent.

Some of my research links

Initial decisions
Our tent has two center poles, no exterior poles, and will be supported by guy lines. (KISS ie Keep It Simple Stupid) Our shoulder is six feet off the ground and our peak is nine. The bell at the shoulder has a 8' diameter, and 12' diameter at the base, and a 4' ridge. The walls will not be sewn onto the roof, but will be two separate panels, to allow for a door on either side of the tent. The rain flap will be an integral part of the roof, nothing to flop in the wind to let rain in. Where the rain flap and the roof meet there will be a 2" reinforced strip, to which the wall ties and the guy lines will attach to. The peaks of the roof will be reinforced by a metal ring and a few straps to prevent the seams from fraying. And there will be another rain flap used to cover the ridge and the peaks. We decided to not use any grommets, and instead we will be using straps. This decision was based on 3 main reasons; 1- Grommets are notorious for ripping out. 2- They can rust. 3- I do not have the right tools to properly set them. 4- The grommets alone would have costed about $60, while using canvas scraps costs us nothing. We will be painting the seams, and waterproofing the tent

So to start off my DH bought 3 large 15' X 12' 12oz canvas tarps online. I then used my sketchup model to create a pattern for the roof and wall panels, making sure to add in 1 1/2" seam allowance for each seam. I then printed it out, transfered it onto my roll of newsprint, and then reinforced the edges with masking tape. After that I played tetris with my patterns and fabric, and eventually got all the pieces cut out, with very minimal scrap. What little scrap I do have I will be using to make my ties.

 As for the painting I found several pictures which showed painted tents. Here are a few of my favorites. I like the detail and the patterns used on the roof. I noticed that most of the tents in the paintings I have found are painted blue, or occasionally red. The patterns are symmetric, and often include gothic arches, crests, geometric shapes, and occasional scrolls. The rain flap was usually solid, not scalloped or daged. the roof could have concentric patterns, patterns along the seams, or both.
Lastly here is a sketch of the pattern I plan to paint onto our tent. I choose not to use the typical blue or red, infavor of purple and green which represent our household colors, and hopefully will match my device when I get around to submitting it.