Poor Man's Photo Etch Parts Pt1

torpedochief · Post by **torpedochief** » Fri Sep 26, 2014 1:07 pm

Brothers and Sisters,
Need some fittings for your beast. What they don't make that? It costs how much? Do it your self. Photo etch is easiest when you apply the KISS theory.
I modified the storage bin on my Tiger since the Heng Long as molded is incorrect. To do this I have to sand the top and fill in the new extensions. So I decided to try my own photo etch.
Here is what you need:
1. Ferric Chloride (PCB etchant Radio Shack)
2. Plasti-Dip, Any color; brush or spray is fine
3. Alcohol
4. A small bit of an old magazine, the cheaper the better. Look for large areas of all white.
5. Clothing Iron or wood burner with transfer button
6. Tape
7. Steel Wool
8. Basic Drafting tools
9. Small bottle of enamel paint. Any color is fine.
10. Brass of the thickness and size you need.
11. Two plastic trays. The take out trays work great. About 2 inches deep.
12. Chemical Gloves
13. Eye Protection
14. Plastic tweezers
15. Ventilation
* Optional
Fish Tank air pump and hose
Wooden Clothes Pin
Thin plastic or rubber mat
Heating Pad
First thing is to do some basic drawings of what you want to make. Be sure you draw your items at least three time size you need. Do not worry about your artistic talents we have ways of taking care of that.
There is a free but powerful image manipulating software called GIMP. It has all the tools you need to make anything you need.
Scan your drawing then open it in the GIMP program. It would take me about 100 hours to explain all the features so I will let you play with it and learn the way I did.
However there are a few tips I will share. Once you have your basic sketch turned into your basic master pattern you can do one of two things. If you invert the black and white you will create either parts or a stencil. Anything black will be protected from etching, where as the white will be removed. Either is very useful, for making marking stencils or parts, or nameplates, bla bla....you get the idea. The next thing is to make the little creases for you to be able to fold your finished parts. To do this make as small a white line as you can where you want the fold to be. We will talk about why in a second. Also if your part needs holes make sure they are white. When you are satisfied click view and increase the zoom. Look for Pixels that are a little off of black or white. Redo these areas until both black and white are as pure as can be.
Now using you laser printer, make a copy. Remember we are still at 3 times the size you need! Look over the printed copy note anything wrong or add a part or delete something.
If everything checks out reduce the image to the size you need. Now print a copy of the image at the scale size. Still okay?
Take the magazine page and cut it a bit larger than the image. Tape the Magazine cutout over the image. Be sure the tape is flat!
More next Time!!

ALPHA · Post by **ALPHA** » Fri Sep 26, 2014 1:23 pm

Very Cool and very handy tip.... Used to do this back in the day.... not even sure if our local radio shack carries the etching fluid anymore...they've changed quite a bit here... not many project builders anymore I guess

Thanks for the instructions...it's a real refresher course

ALPHA

PS. Another way to do it...is to use a photo etch you have and use that as a stencil...

torpedochief · Post by **torpedochief** » Fri Sep 26, 2014 1:31 pm

Friends Here is Part 2

Replace this page in your printer and print a copy so that the image is now on the magazine paper. You see magazine pages are coated in plastic. When you laser copy the plastic melts slightly and soaks in the plastic of the image. Since etchant does not attack plastic you just made your own photo resist!
Carefully un-tape the image the magazine paper from the printing paper.
Prepare your brass. Give it a buff with the steel wool to give it just a bit of a tooth. Use the alcohol to clean it up. When it is clean be sure you do not touch the surface!
Tape the edges down on a flat smooth bit of wood. now place the image on the magazine sheet, be sure the image is face down and in full contact with the brass. Carefully tape this down.
Now to transfer the photo resist image we made to the brass. NOTE: This part is more art than science, so take your time!
I use a transfer button on my wood burner, but you can use an iron also.
If you use an iron be sure to empty any water from it and do not set it on Steam. Remember we are melting plastic not smelting pig iron so use a lower setting. It may take more time but you will avoid problems such as warping, burning the paper, setting the house on fire, and other problems.
When your heating device is heated, rub it over the image gently. Work the iron back and forth, up and down. It should take about three minutes. What is happening in the plastic on the image is heated and melt, The brass heats also and becomes hotter than the paper. The brass treats it somewhat like solder and soaks the plastic and you image in.
Remove the heat and let it cool to room temperature. DO NOT TRY TO PEEL OFF THE PAPER!!!!!!!
When the brass is cool run it under tepid water. The remains of the image are now mostly paper and we are using water to dissolve it. Give it a little rub with you fingers to help it along. You will never get all the paper, but get what you can.
Carefully lay the brass on a square of cardboard face down. Using Plasti-Dip, apply two or three coats, allowing each coat to dry four hours.
What you have now done is sealed the back of the brass with rubber. Etchant does not eat rubber so the area of brass that will become our parts is isolated. This also removes the need for frets, so you do not have to trim the parts. Your parts will be on the rubber. Trust me they are not going anywhere.
Alright here we go. Etchant works better and faster if it is warm and agitated. (My wife is the same way.) NEVER EVER EVER, NEVER heat etchant on a stove or in a microwave!!!!! Boil water, take it off the stove and place your bottle of etchant in the water, letting it heat the etchant.
You can set up a heating pad covered with rubber and to keep the etchant warm during the process. Just be sure you do not spill any. Agitation can be a Fish tank air pump turned way down. Put the hose in the bottom of the tray, secure it to the side with a clothes pin.
Now is the time to have the other tray filled with clean water.
With the etchant heated, place the brass face up into the etchant. After three or four minutes remove the brass and place it in the water. We just stopped the reaction. Why? Remember the fold lines we created? The etchant has dissolved down to where we need and now we need to protect the lines from further etching. To do this we use enamel paint to fill the lines thus protecting them. Let the paint dry before you go on.
With the paint dry return the brass to the etchant. Monitor closely, by lifting it from the etchant to check progress. When the brass around your parts has dissolved, remove the brass from the etchant and place it in the water.
Almost there!! After a five minute soak. Pat dry the brass. Lay it flat. The rubber will make it all floppy. Now you need to find a thinner to remove the photo resist we made. Finger nail polish remover works good, but find a product that works for you.
With the resist removed you now have your parts but, give them a little rub with the steel wool and another rub of alcohol.
When the part is needed just lift and peel it from the rubber backing.
Well there you are! Enjoy!