It's spring, but it will be cold here for a couple more months. My dogs can only go so long without grooming though so I thought I would make them coats to keep them warm in the meantime. First I just put some old T-shirts on them to see what would happen. I've been meaning to cut up a bunch of old, unwearable T-shirts for a while now. Since I had two of the same shirt in different colors, I thought it would be fun to make coats out of them.

The dogs didn't mind wearing the shirts, but the clip I used wasn't secure enough. Stella tripped when it came loose and Izzy's feet got tangled in the sleeves. The coat needed to be more form fitting and have a liner that make it warmer. Lights, like in this Instructable by jesschloehicks, would also make it safer at night.

Tools and Materials:

- Old T-shirt

- 1 yd. (or scraps) of muslin, felt, flannel or other soft fabric

- Sharp scissors

- Cotton thread

- Conductive thread

- LEDs

- Switch

- Coin cell battery holder

- Coin cell battery

- Pins and needles

- Flexible tape measure

- Magnetic purse clasps

- Sewing machine (speeds things up, but not absolutely necessary)

- Dog

Step 1: Mark T-Shirt

Put the T-shirt on the dog inside out. Fold the bottom to emphasize the inside of the dog's hip. Use a piece of chalk or fabric marking pencil to draw a line from there to the spine moving toward the back of the shirt. I drew two lines. One represents a shorter version and the other a longer version that would cover more of her back and hips. I wouldn't usually use a Sharpie, but I wanted you to be able to see it well enough.

Step 2: Cut Shirt

Cut up the sides of the shirt to the beginning of your mark. I folded the shirt over and used a notepad to find that spot on the unmarked side. If you have a T-square, that would be a lot more accurate.

Cut along the line you drew using the one for the longer version (you can always cut it shorter later).

Fold the shirt in half moving the back of the shirt out of the way. Use the first cut to help you cut the second half.

Cut the back of the shirt in half ending about even with the armpits.

Step 3: Test and Mark

Put the coat on your dog. Hopefully said dog cooperates like Stella. I put her harness on over it so it would fit as if we are going on a walk. Check out the length over the hips and butt. You do want it about 1/2" too long so you have some seam allowance.

Wrap the ends under the dog around to the back. Try to smooth them out as much as possible and not to let them twist. Mark where they meet in the center of the dog's back.

Make a mark along the dog's side to make a slot. One of the flaps will thread through so it isn't as bunchy.

(Notice Stella is much less shaggy than previous pictures. Now she needs the coat!)

Step 4: Cut Liner and Attach

Fold the T-shirt in half and then fold the sleeves and flaps on top. Fold the additional material in half and line up the folds. Draw a line around the shirt. Cut along the line.

Line up the right side of your material with the right side of the shirt. Sew around the edge from the side seam to the side seam. The turn the liner and shirt right side out. You can attach the liner along the side seam with the machine, but I'm not great so I hand stitched the inside parts. I wasn't really worried about the raw edge, but you could create a nice hem by folding it over. Don't finish the neck yet! You will need to put the circuit between the shirt and liner.

Step 5: Hem Straps & Make Slot

I added a small piece of the liner fabric at the place where I cut the back of the shirt to reinforce it. Then I folded over the edge of the straps and hemmed each one.

I used the button hole settings on the machine to make a nice slot for the strap using the line I had drawn in Step 3. I made it bigger than the line and wider than a typical button hole. Then I cut away the inside fabric so the strap would fit through.

I put it back on Stella and made sure that the marks I made earlier still lined up well. They did so I didn't have to make any new marks for the location of the clasps.

Step 6: Add Closures

Use the backing piece to help you mark and cut the fabric with two slits. Insert prongs through fabric. Slide the prongs through the backing piece. Fold over the prongs using a pliers to help you. Get them as flat as possible. I placed two on the back on either side of the mark. Place one on each of the straps as well.

Since the liner I used is so thin, I decided to add another pad of felt on top of it to cushion the prongs. I just hand sewed it to the liner fabric on the inside of the jacket.

I finished Izzy's too and just in time for snow! I did learn that they have to wear their harnesses or the arms will trip them up.

Step 7: Sew on LEDs

Plan your circuit by laying out your components on the jacket while it is on the dog. I wanted the battery pack to be under one of the flaps for more protection from rain and snow. Next I drew the route of the circuit out to make sure I would avoid creating a short. This is a simple parallel circuit.

I grabbed a piece of scrap felt that would fit the circuit. I started by sewing down the negative side of the battery pack. Sew all terminals with at least three stitches. I usually use five or six stitches around the battery pack because it's so tiny. Then I sewed to the negative ends of all the LEDs. When I got to the last negative, I tied off.

Then I sewed all of the positive terminals of the LEDs together. I didn't sew to the battery pack; I just tied off. Try to keep your stitches small, neat and tidy without any knots, bubbles or tangles. Cut the ends short.

Sew on the positive end of the battery pack. Then sew to where your switch will connect. You can test the circuit by touching the needle to one of the positive terminals.

Place the fabric with the circuit in place under the shirt. Push the needle through the shirt and attach one side of the switch by sewing through the shirt and the piece of fabric holding the circuit. Sew at least four stitches before tying off. Don't go all the way through the liner. Sew the other end of the switch to the shirt and circuit fabric. Then connect it to the closest positive LED terminal sewing only through the circuit fabric before tying off.

Test your circuit! This Sparkfun troubleshooting document will help you figure out problems.

Step 8: Finish!

I used some little stitches to attach the circuit fabric to the shirt. If you have thread that matches better, you could put more in. I also wanted to leave some space to be able to replace the battery if necessary. Then I put some stitches to close the neck (these would have to be removed to replace the battery) and trimmed the fabric to fit nicely. Again, you could fold the fabric over to create a nicer hem.

Stella is warmer and glows in the dark! I'll finish the circuit on Izzy's next. I'm submitting this to the Trash to Treasure Contest. If you like this idea or plan to make it, please vote! Thanks.