Guide: Foiling
Within this guide you will find all the information required for applying Foil for Foil Construction. This guide assumes you have materials prepared for this step already.
Required Items:
Optional Items:
- Scissors/Thread Snips - Used for cutting the foil or backing paper. You can just tear them instead too.
- Damp Towel - Used to clean the glass prior to foiling if dirty.
- Dry Towel - Used to dry the glass prior to foiling if wet or to wipe off dust.
- Foiling Tool - Device used to help apply or crip the foil to your material.
1. Edge Surface Prep (Optional)
While foil should stick to most things, rougher surfaces will allow the foil to stick better than a smooth surface will. Roughing up smooth surfaces with your Grinder or a Carborundum Stone can help with getting the foil to stick better.
2. Edge Surface Cleaning
Applying Foil requires the surface it is being applied to be free of oils, dirt, dust, moisture and other grime. You are applying a metal tape and if it's not clean it will just fall off or barely stick.
3. Pick Appropriate Foil
Now we need to pick appropriate foil for the material we plan on applying it to. There's lots of options, thus lets go over each part individually.
Foil Thickness
Thickness of the foil determines how easy it is to bend, flex and tear. Thin foil can easily tear while being worked while thicker foil will be stiffer and harder to tear.
| Mil (Thousands of an Inch) | Uses |
|---|---|
| <1 | Don't bother. It will tear like tissue paper, often found as "electronics" foil. |
| 1 | Almost as common as 1.25, Tears easy, Folds easiest, Stretches less when worked. |
| 1.25 | Most common option, Tears moderately, Folds well, Stretches moderately when worked. |
| 1.5 | Least common option, Tears hardest, Folds stiffly, Stretches harder when worked. |
Foil Backing Color
Foil has a couple options for the backing color it has. These backing colors aren't super important but using one or the other may have a very small effect on the look of the project. The color of the backing is an artistic choice that has no other meaning, they all will work the same otherwise.
| Backing Color | Uses |
|---|---|
| Black | Good all around option, Hides edges on clear or Cathedral Glass, Looks good with any Patina. |
| Silver | Best used with no patina on clear or Cathedral Glass, can reflect light back into the glass. |
| Copper | Best used with Copper Patina on clear or Cathedral Glass, Best option for Opaque Glass, can reflect the copper color back into glass which can create unique effects in transparent or semi-transparent glass. |
Foil Width
This is your most important part of the foil as the width determines how wide your solder joints will end up being and the foil must be wide enough to hold the parts you have in place by wrapping over the front and back faces.
| Width | Uses |
|---|---|
| 5/32 | Used on thin glass or for other specialty applications. Barely covers the edge of average Sheet Glass. |
| 3/16 | Common to use for those wanting fine lead joints with average Sheet Glass. Does not work well for uneven/highly textured average Sheet Glass. |
| 7/32 | Most common and popular size. Works well for most glass and textures. |
| 1/4 | Common beginner size due to how easy it is to work with. Looks more like Came when used. Works for almost all average Sheet Glass. |
| 5/16 and larger | Not commonly used outside of super wide lead lines, decorative foiling or for foiling thick/heavily textured glass as the extra can be easily trimmed back when custom sized foil is needed. |
4. Applying Foil
Apply the Foil
This is where foiling can get tricky as there's many ways to peel back the paper and apply the foil.... there's no one technique that is perfect and there's even tools to help that you may have different results with. Regardless of what method or tools you use the goal is the same, get the foil on so it's evenly overlapping the front and back faces of whatever is being foiled.
So let's split this into parts and feel free to try a bunch of things! Including things not covered here!
Before we get started, we need to talk about concave parts. These parts will be more difficult to work with due to the foil wanting to pull straight, Foil Splits occurring and the possibility of tools not fitting in places. They will require you to slow down and give them a bit more attention!
Foiling by Hand
There are many ways to apply foil with your hands and what works best for you will depend on your personal dexterity and hands. It's difficult to cover every way possible due to this, thus this is a generic tutorial picking out the easiest way possible for most.
Picking the Starting Side
Internal Parts
Which side the foil is started isn't particularly important when a part is completely surrounded by other parts.
Edge Parts
Start your foil on an Inside Joint rather than on the outside edge. The overlap point is weak and prone to issues so keeping them inside results in stronger edges.
Edge Parts when using Came
When using came foiling the edge isn't needed and often skipped to save on time and foil. When this is the case we will always start on the outside edge and wrap around the Inside Joints ending on the outside again.
Foiling Away or Towards Yourself
When hand foiling you can decide what way you feed the foil and the direction you work around the part. There's no massive difference between them but they can give you different results if you are unsure of what is best for you, try them all!
| Feeding Foil | Turning Part | Comments |
|---|---|---|
| Towards | Away | Works well for larger parts. |
| Away | Away | Hard to line up as what you line up will move away from you. |
| Towards | Towards | Common to do by feeding foil across the hand or through the fingers and controlling it by spreading fingers out. |
| Away | Towards | Gives you a nice top down view, won't work with larger parts. |
Setting the Start Point
Once you have decided if you need to start on a particular side we can start the foil. You are going to start the foil around a corner if there is one, if there is no corner then pick an area with the most protrusion or if none exist anywhere.
Peel back the paper from the foil a short distance but not too far it's unruly.
Hold your part in the other hand pinching the top and bottom face between your thumb and pointer away from where you plan to start or hold the part on the edges with multiple fingers. On parts that it doesn't matter what side you start, pick the side that is most comfortable or the easiest for you to hold the glass for.
Take the tail of the foil and stick it on as centered as possible right near the corner and rotate to the next side right away while holding the foil taught.
Continuing Around
Now we have an anchor and can keep the foil taught and line it up along the edge as work around the part pressing the foil against the glass. Keeping it taught helps with alignment as it can't bend or fold easily. Keep working your way around the part until you get back where you need to end.
In some cases you may need to burnish down one side or use your fingers to press one side down to hold the part so you don't mangle the already applied foil. Just do this as needed when you run into it.
Internal Parts and Edge Parts
Once you get back to the start point you want to overlap the start tail and then end the foil some.
Edge Parts when using Came
Wrap around until you get to the next outside edge and wrap around it slightly. This helps anchor the foil in place on the ends, much isn't needed so don't over do it else you may need to trim it back,
Done
Now the part is foiled and ready to Burnish
Foiling with Tools
As there's lots of tools that exist they will each get their own page for detailed instructions. Though they all follow the same general idea.
- Pick the correct tool/parts for the width of foil you are planning on using.
- Thread the foil through the tool.
- Set any gauges, stops or other things the tool may have.
- Run the tool along glass or run the glass through the tool till you get back to the start.
- Cut or tear the foil so that it overlaps the start point if you didn't go past it.
- Move to the next step!
| Todo: Put them here someday hah. |
Crimping & Burnishing
Now that we have the foil on the glass on the edge, we need to fold over the bits hanging out. This can be done in one or two stages depending on what shape the part is and what you are comfortable with. If you used a tool it may have already crimped the foil down for you.
- If you did not use a foiling tool, Grab your Fid, Lathekin, Marker, Pen or other hard smooth object. Using light to medium pressure, press the foil that you placed on the edge all the way around so it sticks in place good.
- (Optional) Crimp the foil with your fingers or tool by just pinching/pushing it over the edge.
- While making sure you are holding the tool flat against the glass, using light to medium pressure, press the foil down so it's nice and smooth on one side. What part of the tool you use doesn't matter as long as it's making full contact.
- When you get to a corner make sure to fold it so that the adhesive side is down.
- Repeat steps 1-4 or 3-4 as required.
- Flip the glass, repeat.
Done!
If everything went well and to plan you are ready for soldering!
Tips, Tricks, FAQ
- When burnishing small parts it might be beneficial to complete one whole side so you have a decent spot to grab the part.
- Placing the part on the table after crimping to burnish is also a good option if you can't hold it or don't want to. Just make sure the corners are folded down or you could bend them the wrong way!
- If a corner or any section of foil is showing the adhesive side you need to try and correct it. Solder will not stick at that location.
- If you have any Foil Splits or other damaged foil you will need to Repair it before soldering as the solder will only stick to the foil and nothing else.
- Foil can easily be trimmed with a craft knife! Get creative!
- Why does my Foil not stick?
- Foil does have a shelf life! Even sealed the adhesives can dry out and not stick anymore. Once open foil will dry out faster. While you can still use it, it's not enjoyable. You can test the foil by sticking it to a fingernail and pulling. It should peel like tape and not just pop off.
- Why does my foil always tear in this spot?
- Foil while malleable can't just be pressed flat in all spots, try gently pushing it over a little at a time going back and forth across it until it's flat. TODO: make a gif of this.
- Help! I changed my mind about the patina for the solder!/Do I need to match my foil with my solder?
- It's fine! Do what you want! It may look better matched but you probably won't notice unmatched in most cases. Most people wouldn't know the difference anyway.
- My foil is way too wide but my smaller foil is too small!
- Ah yes, when you need an in-between size but it doesn't exist. The easiest option is to line up the overlap on the FRONT SIDE of the glass so it looks correct and put all the extra on the back. Then use a craft knife to trim it so it's the right size! That way you don't need to trim it two times!
- How do I get foil into deep/small textures?
- This is a tricky one.... Depending on the texture you may just end up Splitting the foil tons. In cases like this using something like a Ripple Bit or Face Grinding to reduce the thickness changes would be beneficial. Otherwise just get it as close as possible. It isn't really noticeable unless using a backing that doesn't match the solder finish. It also won't really affect the strength at all.