Hi
In this section MATERIALS we are going to look at the main materials required to get up and running in your etching pursuits.
Possibly the most indispensable material is the resist, this has a number of functions and using the correct resist for your project is important and knowing the correct thickness of the resist you require for each individual technique will make your task easier and definitely save you money.
Resists comes in a number of materials from air brush mask, Fablon, (known as sticky backed plastic from Blue Peter) vinyl used in sign making, PVC, rubber and for fine detail and photographic imagery there is photo resist, which I will look at in a separate post.
Rapid mask photo resist
It comes in a variety of sizes from A4 sheets to rolls of 1200mm wide and every size in between and no doubt wider.
It can come in ready made patterns of cut vinyl or ready exposed photo resist reusable stencils
Pre-exposed stencils.
and of course just plain old resist on a roll.
The first resist I bought was called Buttercut or Butternut (can't quite remember) I ordered around 600mm wide by 2m long, it came from a large stained glass supplier and it arrived folded into a tight parcel to fit into a jiffy bag, this was very expensive resist and was now useless for what I required it for. They did replace but do be careful with your resist as it needs to be perfectly stuck to your glass to prevent blow through which is what may happen with creases and bubbles in it.
Vinyl, PVC and rubberised resists come in a variety of thickness and understanding the thickness can be a little difficult because it is not measured in what for the majority of people are recognized measurements.
Resists comes in a number of materials from air brush mask, Fablon, (known as sticky backed plastic from Blue Peter) vinyl used in sign making, PVC, rubber and for fine detail and photographic imagery there is photo resist, which I will look at in a separate post.
Rapid mask photo resist
It comes in a variety of sizes from A4 sheets to rolls of 1200mm wide and every size in between and no doubt wider.
It can come in ready made patterns of cut vinyl or ready exposed photo resist reusable stencils
Pre-exposed stencils.
and of course just plain old resist on a roll.
The first resist I bought was called Buttercut or Butternut (can't quite remember) I ordered around 600mm wide by 2m long, it came from a large stained glass supplier and it arrived folded into a tight parcel to fit into a jiffy bag, this was very expensive resist and was now useless for what I required it for. They did replace but do be careful with your resist as it needs to be perfectly stuck to your glass to prevent blow through which is what may happen with creases and bubbles in it.
Vinyl, PVC and rubberised resists come in a variety of thickness and understanding the thickness can be a little difficult because it is not measured in what for the majority of people are recognized measurements.
Take a look at the these pages from MDP;
The thickness is measured in mils or microns or the symbol µm.
What does it mean;-
1 Micron = 1µm =0.001mm or 1000th of a mm
80 µm = 0.08mm Light duty for glass from 2.50 per metre
180µm = 0.18mm Medium duty for glass from 3.00 per metre
330µm =0.33mm For heavy duty for stone, metal from 7.50 per metre
So a basic understanding is that the bigger the number the thicker the resist, the thicker the resist the higher the cost, the higher the cost the more you might look for a cheaper alternative when depth of the etching / carving is not an issue.
Of course this is just one way of a company displaying the thickness.
Some companies display in 1000th of a inch or thou an older measurement that is still used in the engineering world (not by me) which since decimalisation has largely disappeared but the conversion I use at work is 40 thou = approx 1mm.
1 thou = approx 25µm so from the above 80µm is approx 3 thou 180µm is approx 7 thou and 330µm is approx 13 thou.
It is not only the thickness of the material that effects the resistance to attack by the media at what can be a hugely concentrated pressures, some sticky backed plastic can be thicker than resist yet not have the resilient qualities designed into quality resist also the adhesive used plays a major part. The adhesive is designed to resist movement yet also have the ability to be easily removed, a difficult combination to achieve.
The technical data sheet above it tells you the value's of the adhesive used.
Getting bored yet.
Knowing the alternatives and how far you can push them is an important part of the learning curve, this is where testing and practise comes in.
I started on sticky backed plastic which is sold in Wilkinson's and other types of General stores then when I bought my 2nd used cutting machine it came with around 6 full rolls of vinyl which would have cost more than the cutter to buy. I then after practising with these cheaper resists moved onto the more expensive materials, even now I shall use cheaper / thinner resists for light etching work. Vinyl is around 50 to 70µm.
Unfortunately vinyl does have one major drawback compared with proper resist in that it is designed to stay on what it is stuck on. Ha! as we say in England "it's a bugger to get off"
Have a read, these people know what they are talking about.
Etchmaster - Understanding resist
Etchmaster - Basics of resist
Norm Dobbins - Resist
MDP Supplies UK - Prices
Application Tape
Things that go hand in hand,
Gin & Tonic, Fish & Chips, Resist & Application Tape.
When a cut pattern of resist is transferred to a piece of glass then application tape is used to apply it to the glass hence the name application. (also called Transfer tape)
Alternatively the resist can be stuck directly to the glass, the pattern then drawn on and cut directly into the resist in this case no application tape is required.
Application tape comes in 2 different forms and many different width's
Paper tape
Clear tape
I use both the paper type and the clear, the clear is a little more expensive and I use for the smaller jobs such as glasses or small panels where centering is important. The paper tape I use for larger flat panels where the edges require lining up and not centering.
Resist consists of 2 layers, the resist on the top and a silicone base card which it is lightly stuck too, the silicone acts as a release agent for the resist glue so it is easily removed but makes the two layers act as one for easy handling and machine cutting.
The resist pattern can either be cut by hand or machine, but once cut you need to transfer the cut pattern to the glass removing the backing card at the same time, without some means of holding the pattern together it would end up as a mess on the glass (done it).
Paper tape being applied, a application roller is not necessary but for larger pieces can be very helpful.
No bubbles, smooth application is important and care should be taken to smooth evenly.
A hard plastic vinyl squeegees are readily available on ebay for a few pound.
The application tape is used as a third layer, base card - resist - tape, a resist sandwich so to speak.
This resist now has adhesive to both sides so the base card can be removed without a big mess being made.
Weeded stencil applied
Backing base removal
Tape being removed
Off course there is are a number of techniques to achieve this which shall be looked at in a later post.
Paul
The thickness is measured in mils or microns or the symbol µm.
What does it mean;-
1 Micron = 1µm =0.001mm or 1000th of a mm
80 µm = 0.08mm Light duty for glass from 2.50 per metre
330µm =0.33mm For heavy duty for stone, metal from 7.50 per metre
So a basic understanding is that the bigger the number the thicker the resist, the thicker the resist the higher the cost, the higher the cost the more you might look for a cheaper alternative when depth of the etching / carving is not an issue.
Of course this is just one way of a company displaying the thickness.
Some companies display in 1000th of a inch or thou an older measurement that is still used in the engineering world (not by me) which since decimalisation has largely disappeared but the conversion I use at work is 40 thou = approx 1mm.
1 thou = approx 25µm so from the above 80µm is approx 3 thou 180µm is approx 7 thou and 330µm is approx 13 thou.
It is not only the thickness of the material that effects the resistance to attack by the media at what can be a hugely concentrated pressures, some sticky backed plastic can be thicker than resist yet not have the resilient qualities designed into quality resist also the adhesive used plays a major part. The adhesive is designed to resist movement yet also have the ability to be easily removed, a difficult combination to achieve.
The technical data sheet above it tells you the value's of the adhesive used.
Getting bored yet.
Knowing the alternatives and how far you can push them is an important part of the learning curve, this is where testing and practise comes in.
I started on sticky backed plastic which is sold in Wilkinson's and other types of General stores then when I bought my 2nd used cutting machine it came with around 6 full rolls of vinyl which would have cost more than the cutter to buy. I then after practising with these cheaper resists moved onto the more expensive materials, even now I shall use cheaper / thinner resists for light etching work. Vinyl is around 50 to 70µm.
Unfortunately vinyl does have one major drawback compared with proper resist in that it is designed to stay on what it is stuck on. Ha! as we say in England "it's a bugger to get off"
Have a read, these people know what they are talking about.
Etchmaster - Understanding resist
Etchmaster - Basics of resist
Norm Dobbins - Resist
MDP Supplies UK - Prices
Application Tape
Things that go hand in hand,
Gin & Tonic, Fish & Chips, Resist & Application Tape.
When a cut pattern of resist is transferred to a piece of glass then application tape is used to apply it to the glass hence the name application. (also called Transfer tape)
Alternatively the resist can be stuck directly to the glass, the pattern then drawn on and cut directly into the resist in this case no application tape is required.
Application tape comes in 2 different forms and many different width's
Paper tape
Clear tape
I use both the paper type and the clear, the clear is a little more expensive and I use for the smaller jobs such as glasses or small panels where centering is important. The paper tape I use for larger flat panels where the edges require lining up and not centering.
Resist consists of 2 layers, the resist on the top and a silicone base card which it is lightly stuck too, the silicone acts as a release agent for the resist glue so it is easily removed but makes the two layers act as one for easy handling and machine cutting.
The resist pattern can either be cut by hand or machine, but once cut you need to transfer the cut pattern to the glass removing the backing card at the same time, without some means of holding the pattern together it would end up as a mess on the glass (done it).
Paper tape being applied, a application roller is not necessary but for larger pieces can be very helpful.
No bubbles, smooth application is important and care should be taken to smooth evenly.
A hard plastic vinyl squeegees are readily available on ebay for a few pound.
The application tape is used as a third layer, base card - resist - tape, a resist sandwich so to speak.
This resist now has adhesive to both sides so the base card can be removed without a big mess being made.
Weeded stencil applied
Backing base removal
Tape being removed
Off course there is are a number of techniques to achieve this which shall be looked at in a later post.
Paul
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