Soldering
Techniques
This article deals with soldering of lead came, copper foiled projects and zinc.
Lead
Came
Tools
A
soldering iron of sufficient power and temperature is required –
soldering tools. This will normally be a 100 watt rated
iron with a 700F degree bolt (or soldering tip). An additional
rheostat is not required or desirable.
Usually,
40/60 solder/tin alloy solder is appropriate for soldering lead,
although 50/50 also works well. The differences in melted and solid
states is given in the table here.
The
lead needs to be clean and bright to start with. If it's fairly new
lead it should be solder-able without more than a scrubbing of the
joints with a brass wire brush. However, if the lead is dull and
oxidized, you should scrape the lead in the area to be soldered with
the blade of a lead knife or leading nail until the bright metal is
revealed. This is required because the oxidised surface interferes
with the adhesion of the solder to the metal.
The
iron is held over-handed (as you would a tennis racquet) in order to
get the handle low enough to have the tip flat on the lead. Allow the
weight of the soldering iron to do the work for you. Let it rest
briefly both edges of the joint and apply the solder at the front of the iron's bit. Take the solder away from the iron so
it doesn't become attached to the joint. As soon as the solder
spreads, lift the iron straight up.
Avoid
"painting" or dragging the iron over the solder. The object
is to have a shiny, smooth, slightly rounded solder joint. There
should be no points sticking up from the solder joint. If a solder
joint is not satisfactory you can reflux and re-heat. Don't apply too
much solder. It's easier to add more solder than to remove excess.
The
most common concern is whether there is enough solder on the joint.
Very little solder is required to stick the joints together. Often a
securely soldered joint will still show the ends of the cames. You can sweat a joint and get as good (and in some way a more lasting) joint as by having a bead. That is because by adding the minimum of solder (sweating) you will have to get the base metal hot for the thin layer of solder to flow. For
cosmetic reasons it is usual to use enough solder to disguise the
ends of the cames. It is not a structural requirement.
Copper
Foil
I Tools
and Materials
Iron
The
iron temperature needs to be higher than for lead because so much
more solder is being melted for the beads that are the feature of
copper foiled projects. Temperature controlled irons have
interchangeable bits with different temperatures indicated. An 800F
rated tip (noted by the number 8 stamped on the base) is the most
common tip used for running beads. For decorative work you may wish
to use a 600F or a 700F tip to achieve effects requiring lower
temperatures.
Tip
size
Some
people recommend a smaller tip size for copper foil work. This is
done on the basis that the width of the solder bead is narrow and
that with a smaller tip less of the heat will get to the glass. This
is a common sense idea that is not borne out by the studies.
The
glass will get hot under the solder whether a wide or narrow tip is
used, because the solder needs a minimum temperature to melt.
The
narrower the tip is the less heat it has stored, and so the soldering
will be slower than with a wider tip. A 6 mm tip is tempting, but a
10 mm tip is better because the frequency of pausing for the
temperature of the iron to catch up is reduced.
Since
the solder has a surface tension, the bead will form appropriately
whether a small or large tip is used. The bead can become too large
if too much solder is applied, but that is not due to the size of the
tip.
Solder
The
solder used for copper foil is commonly a 60/40 tin/lead composition
or even 63/37, as its melting and solid states are almost the same
temperature. The table given in the section on soldering materials
gives the melting and solidifying temperatures.
II Techniques
Smooth
solder joints
Good
smooth soldering occurs when the temperature of the iron is correct
for the job and the solder being used.
The
problem of bunched up solder or peaks as you lift the iron from the
solder is caused by the iron being slightly too cool for the job and
the solder being used. Looking at the conditions causing the problems
may lead to a better solution.
If
the problem is caused by the iron being slightly too cool to let the
solder flow properly, this can be caused by a number of things.
If your iron is too low power, you may start out well and have the problem develop as you solder.
If
your iron is high enough power and you're using a 'rheostat' or
dimmer controller, this has the effect of lowering the iron's power
and the problem will occur as above.
50/50
(tin/lead) solder requires a hotter iron than 60/40 (tin/lead) solder
to keep the molten metal flowing properly.
The
best possible soldering iron controller is a genuine temperature
controlled iron, where the iron’s controller maintains the tip
temperature by applying full power to the heater when the tip cools
slightly, but otherwise just 'idles'. If you can't get (or afford)
one of these, possibly the best would be to get a higher power iron
or throw away the 'rheostat' or dimmer 'controller'.
If
the problem still occurs, then use 60/40 solder – which melts and
solidifies in a narrower range than 50/50 - or perhaps do the
soldering in shorter 'bursts', letting the iron recover for a half a minute before starting again.
In any case you need to match the speed of movement and the speed of feeding the solder to the iron according to the capability of the iron to adequately melt the solder.
Flux
Also
you have to ensure that the foil has been properly fluxed. This is
done by applying a thin film of flux. This is an area where little
is good and a lot is bad. Over fluxed foil leads to a lot of
sputtering as the excess flux boils and breaks through the hot
solder.
Tinning
Tinning
is the application of a film of solder over the fluxed foil. This
helps protect the foil from oxidisation while working on the project.
I fit and foil all the pieces for the project. Then I tin each piece
separately on all edges. I re-assemble the project and add a very
thin film of flux before tack soldering everything into place. Some
people tin the whole project without taking any pieces out of the
panel as I do. This seems to work well too.
The
object of tinning is to make the running of the bead as simple and
quick as possible, knowing that you will have made it easy for the
solder to flow through to the other bead.
Soldering
Techniques
My
experience leads me to say that the tip of the iron should be in
contact with the surface of the material being soldered. If the metal
is not hot, it will not take the solder well. In the case of copper
foil, the metal is so thin it will heat up almost instantaneously.
The solder should be added to the heated metal to obtain a good
joint. All the advice to hover just above the surface and allow the
molten solder to heat the metal below seems to make for hard work
suspending the iron, and for possible cold joints.
The
principle is that both metals should be hot for a good join. In
leaded work you can sweat a joint and get as good (and in some way a
more lasting) joint as by having a bead. That is because by adding
the minimum of solder (sweating) you will have to get the base metal
hot for the thin layer of solder to flow. I feel that many people do
not understand the principles of soldering, but look only to the
finish. It is possible to have a beautiful joint, or bead and have
the joining of the metals technically weak.
The
strength of a copper foil panel comes from the glass of course, but
also the formation of a “came” with a fin of solder connecting
the top and bottom beads. This means the glass should be fitted
together with a tiny gap between each piece.
The Tiffany method allows for fine detail and yet at the same time it
is imitating the creation of lead came. If you tightly pack the
pieces together you are only soldering a bead top and bottom and no
"heart" is created. By creating a bead on top and bottom
it is possible to enclose flux within the panel.
It
is important to reiterate that a bead is required on both sides of
the panel for strength, even though the bottom may never be seen as
on a lamp. It is only by having a top and bottom bead joined by a
“heart” that you produce a strong panel.
Solder
application
The
solder is applied in one of two ways. The quickest method is to feed
solder in on the thicker part of the shiny soldering iron tip and let it flow down
to the foil. The iron is held against the foil and pulled along the
foil (which has been fluxed) at the rate that allows the solder being
fed to the iron to produce a slightly rounded, shiny solder bead.
Don't try and "float" the iron on top of the solder, be
gently resting against the foil. This requires practice to match the
speed of movement and the amount of solder fed to the iron.
Alternatively,
you can do the patting method. This is easier to control and is done
by soldering one tip-length, lifting the iron and soldering the next
tip-length, barely re-heating the section just soldered.
Another
variation is to place blobs of solder at regular intervals along the
foiled and fluxed joint and then move the iron along the joint
melting the blobs as you go. This avoids the tide marks at the
cooling ends of the solder bead.
Even
Solder Beads on Edges
Running
an even bead on the edges of copper foiled projects is often
difficult, but several things can help.
Ensure
the edges have been tinned all around. Add a thin film of flux to the
tinned edges. Then hold the panel vertically and ensure the edge you
are applying solder to is horizontal. This means that you have to
keep moving anything that is not rectangular.
To
apply solder and move the piece ideally needs three hands – one for
the solder, one for the iron, and one to manipulate the piece.
Failing such an evolutionary leap, you can use a small vice to
continually alter the angle of the edge; you can get a friend or
colleague to manipulate the panel; or you can place the solder so
that you can pick up little drops of solder and place them on the
edge. With practice, you can pick up some solder and transfer it to
the edge before the previous dot of solder has cooled, so leaving a
smooth bead by the joining of the dots.
Alternatively,
you can place dots of solder near each other around the piece. You
then come back and with one hand manipulating the piece the other can
use the soldering iron to heat and join the dots.
You
do have to be careful that you do not move the panel before the
solder has hardened, or it will run down the newly created slope to
the new horizontal edge.
I
find that it is much more difficult to run
a bead on an edge than it is to “pat” the solder dots. This
patting motion allows the solder to join together, but does not heat
such a long line that it flows as you turn the piece to keep the edge
currently being soldered horizontal.
Building
up the edge of sun catchers helps the foil from being ripped off
accidentally, or just peeling back on its own from being damaged
during the cleaning process. This edge soldering will also allow you to bury a
length of fine wire around the outer edge of the sun catcher. This
provides reinforcement, especially if the sun catcher has a design
that has a part of it sticking out on its own, unsupported by the
main body of the piece.
Tack
Soldering
Tack
soldering is the placing of a small amount of solder on the foil to
hold two or more pieces together, so the main soldering can be
performed without disturbing any placing of the remaining pieces. It
is particularly important in 3D projects.
The
advantage of tack soldering is it can allow you to completely
eliminate framing if you are in a hurry. You can just hold two pieces
together with one hand and spot a dab of solder to hold them
together. You don't have to do this for all pieces - just enough of
the outside pieces to hold the whole project together. Although it
is more certain to have everything placed just as you want throughout
the process by tack soldering the whole project. Once you've tack
soldered, everything will be held in place and you can just run the
beads without further considering the placing of the pieces.
For
free form shapes, tack soldering the whole is always quicker. You may want to
use nails or tacks to hold all the glass in place while you tack
solder.
With
big foil projects or ones that have to fit into a predetermined
dimension, tack soldering ensures there is no growth through movement
of the pieces.
It's also a quick way to avoid having to fiddle with each piece to make sure
each is exactly lined up before starting with the running of the
beads.
Soldering
3-D Pieces
When
soldering 3-D pieces together, first tack the panels together with a
single tack at each end. If it later turns out that there is an
alignment problem, it is much easier to dis-assemble a few tacks,
with a piece of paper or thin aluminium inserted into the space
between the pieces of glass and moved up into the molten solder while
your iron is at the tack joint. The paper will strong enough to move
through the solder, separating the two piece of glass as will the
metal.
Once
your 3-D piece is tacked together, turn the piece over
on its side, and, using 50/50 or 40/60 solder, fill in the inner
seams, moving the piece around. Be careful to support the piece with
boxes or blocks and by holding it at the top part above where you are
soldering, to prevent the piece collapsing.
Once
the inside of the piece, say a panel lamp, has been soldered smoothly
with 50/50, turn the lamp over. Get a few boxes or similar supports
to prop the lamp up against, and make it so that there will be a
level solder seam. Using the 50/50 solder again, fill in the seam. It
doesn't have to be perfect, at first. Do all of the seam filling
first, to ensure the stability of the piece. Then go back with 60/40
solder and, again making sure the lamp seams are level, finish by
smoothly soldering each seam. Both the solders have the same melting
point, but because the 60/40 solder solidifies only one or two
degrees below the melting point, there is not enough time and heat
for the solder below to liquefy and drip, if your rate of soldering
is sufficiently rapid.
Even
Solder Beads
Getting
even solder beads is a lot about where you look while you solder.
Unlike drawing or cycling looking at where you are going is not so
useful when soldering. You need to see the effects of what you are
doing so looking behind the solder bit will help you understand what
you are doing. If the bead begins to get small or narrow you either
slow down the forward movement of the solder bit or add solder to it
more quickly. If the bead begins to get too thick, you do the
opposite. You can move the bit faster, or reduce the speed of feeding
the solder to the bit.
Another
element in getting an even bead is the heat being delivered. If you
use a wide soldering bit you are delivering more heat to the joint.
You hold the chisel bit so that it runs along the foil. The bigger
the bit, the more heat is being held. And the more heat held in the
bit, the more heat is applied to the soldering. Small bits are for
getting into tight spots and for decorative soldering. Big wide bits of about 10 mm are best for running beads.
Moving
Pieces
To
keep pieces from moving about as you solder them, use pins or nails
to keep them in place. The best is to assemble the whole panel and
then keep them in place with a frame or lots of nails/pins around the
outside. This keeps pieces from moving and also keeps the panel to
the original size.
The
type of nail or pin will depend on the work board you are using.
Softer boards allow push pins of various sorts to be used. Harder
boards will need nails.
If
you don’t like assembling the whole before soldering, you can
confine the pieces you are currently soldering with nails/pins in the
same fashion as for the whole panel.
It
also helps to do a little tack soldering before the process of
running a bead begins. A small amount of solder on the copper foil
where pieces join will keep the pieces in exact alignment while you
are running a bead.
It must be emphasised that assembling the whole and tack soldering the pieces produces the best result in terms of having all the pieces aligned correctly throughout the panel.
III Special
Conditions
Soldering
small pieces
No-foil
approach
One approach is to have some of the pieces held by over-beaded solder without foil, but it is patchy at best and likely to lose pieces in the long term.
One approach is to have some of the pieces held by over-beaded solder without foil, but it is patchy at best and likely to lose pieces in the long term.
Bevel
approach
The
best approach is to partially 'bevel' the edges of each piece on both
faces. Grind at 45 degrees until the very edge is only 1 mm thick.
Then use foil that is 4 mm wide for 3mm thick glass. For 4 mm glass,
you will use 5.4 mm foil. Make sure that the foil covers only the
bevelled edges and does not extend outside them by trimming if necessary.
You
solder into the 'V' formed by the bevelled edges. Don't over- fill
the joints as you don't want solder outside the 'V'. It also is best
if the panel is supported underneath the area being soldered.
With
the solder contained by the 'V', the solder lines will be of constant
width throughout the entire panel. It is best to practise this technique on
some scraps before you start the main job.
This
approach will minimise the amount of light blocked by the foil -
important with tiny pieces - while still providing the strength of
fully foiled pieces.
Trimming
approach
If
you have to have really small pieces, just foil them as you would any
other piece, and burnish it as normal. Then take a very sharp craft
knife and trim the foil so that just a little tiny bit of foil is on
the front and back of the piece.
No
glass approach
Tiny
pieces are really tedious to work with. So if the piece is going to
be black or really dark, for example, a small hummingbird's beak, or
a bird’s eye, don't bother with glass but just fill the space with
foil and solder.
Tinning
Brass
Brass
transmits heat much more quickly than lead, so a considerable length
or the whole of the piece, e.g., a vase cap needs to be heated to
avoid the cap acting as a heat sink and so not allowing even tinning
of the object.
When
tinning any brass pieces, like a lamp cap, rub it with fine grade
steel wool, wash the residue off and dry. Then apply flux with a
fresh flux brush, and hold the piece with a pair of pliers.
At
this point you can heat the vase cap with a low heat blow torch to
warm the whole piece. When warm, turn off the blow torch and begin
applying the solder with the soldering iron.
Alternatively
you can work without the blow torch. Apply a bit of solder to the tip
of the iron. Touch the piece with your hot soldering iron, let the
piece heat up a little, and then start moving the iron slowly and
smoothly over where you have applied the flux.
When
the whole piece has been covered, wash it, dry, and then inspect for
any missed spots or unsightly solder blobs. Apply a little bit more
flux and touch with your soldering iron. If you are doing a lot of
this kind of work, an 800 degree iron tip will speed up your work.
Soldering
Fragile Pieces of Glass
Heat
transfers to the glass during soldering. Normally this does not
produce any difficulties. However with slender pieces, deep curves,
or band saw cuts, the heat generated by soldering can crack or break the
glass. This means that you need to ensure that you do not linger for
a long time on the solder beads along these kinds of pieces.
You
can do several things:
- Solder roughly at first, and then continue soldering somewhere else on your piece, to let the heat of the solder dissipate before finishing soldering by filling the gaps in the bead. The glass does not need to be cold before coming back to solder. Glass breaks because it is hot in one place and not throughout the piece. So, soldering warm glass has less chance of breaking due to heat shock.
- Create the bead in a single relatively swift pass. It has to be slow enough to produce a bead, but not linger in any area. The bead should not be so large as to turn over on itself. It should produce a dome shaped bead and be similar to a quarter or at most a third of a circle.
- Build the bead up with a series of “pats” along the copper foil joint. This involves putting a dot of solder to the copper foil tape and resting long enough for the solder to spread to its natural dimensions, and then place another dot at the leading edge of the first and so on until you reach the end of the line. This provides a relatively cool method of soldering. Its disadvantage is that it leaves a number of “tide” marks at the cool end of the bead. These can be changed to a single tide mark by re-melting the solder at that end.
Soldering
Radiating Lines
Some
times no matter how you try to avoid it in the design, you end up
with multiple solder lines joining at one point.
In
copper foil work, I find it best to tin all the copper foil before
assembly, as this means you can use a minimum of solder to solder the pieces to one another.
You
will be left with less solder at the joint if you start from the
joint and move away from it while soldering. This drags the solder
into the bead line rather than letting the solder build up at the
joint of the multiple lines and give a resulting high point resulting
from the accumulation of solder there.
Soldering
Zinc
Brass,
copper and zinc are heat sinks. That is, the metal conducts the heat
rapidly so more heat has to be applied than for lead and tin to keep
the soldering site hot enough to accept the solder.
The
important elements are:
Use
a hot iron. If you use a rheostat, turn it up to full. If you can,
change the tip/bit to one rated at 800F – it will have an “8”
stamped on the end that goes into the barrel of the iron.
Ensure
the joint is really clean. Zinc develops a film of oxidisation very
quickly.
Apply
the flux liberally at the soldering point to ensure the area is
“wetted” and kept free of corrosion products.
Keep
the iron in contact with the zinc came for a few seconds to heat the
metal.
When
the came is hot, apply the solder to the bit. Keep the bit on the
metal until you see the solder begin to flow, then gently lift
directly up.
IV Problem
Solving
Foil
pulling away from the glass on perimeter
If
this is happening to you, there are several things to remember.
Clean
all the edges and surfaces just before foiling. This ensures there
are no oils or oxidisation to interfere with the contact adhesive of the foil. Avoid
hand creams just before foiling as this increases the amount of oils
getting onto the glass.
Remember
that lots of heat breaks down the adhesive. So do not remain in one
place too long while soldering. However the adhesive is not the
element that keeps the foil attached to the glass in the long term.
Instead, think about whether the bead on the edge is thick enough to
provide the rigidity required without relying on the adhesive of the
foil. Also, does the bead curve around to the face of the panel?
Finally,
think about whether an edging came would provide better support and
finish to the piece.
Foil
Lifting While Soldering
There
are several possible reasons for this.
The
main one is that the soldering is too slow. This causes the adhesive
on the foil to fail before the solder has a chance to become rigid.
The
foil may not have stuck to the glass firmly. Reasons for this are
many, but some are:
- Dirty glass. Make sure the glass is washed and polished clean, especially if you have been grinding, when you need to get all the glass dust out of the pits on the edges.
- Oil from the cutter.
- Oils from your hands. The oils can be natural or from hand creams. If you have oily skin or need to use hand creams consider cotton gloves for use when handling the glass prior to and during foiling.
- Inadequate contact between the foil and the glass. This can be from both the above, but can also be that the foil was not pressed firmly to all the sides and edges of the glass pieces.
The
foil adhesive may be inadequate through manufacture or age. If a test
piece does not feel tacky to your finger tips, it is not going to
stick to the glass very well.
Exposed
Foil
After
soldering, inspect the solder seams for small areas or strips of
copper foil edges that aren't covered with solder.
If
this exposed foil is where you want the solder bead to be, you need
to clean the foil and re-apply solder. Usually scrubbing with “000”
steel wool is sufficient. If, after scrubbing and applying flux, the
solder still does not stick, you need to wash the piece and after
drying, scrub the exposed foil, re-apply flux and solder again.
If
the exposed foil is surplus or where you do not want any solder, take
a craft knife, and carefully trim off the exposed foil.
Filling
Gaps Between Glass Pieces
Gaps
along the bead line
When
you have a significant gap between pieces of foiled glass, fill the gap with
small pieces of lead or copper foil tape that has the adhesive side
folded together. These will have to be cut to a width of just less
than 3mm to keep them from projecting above the surface of the glass.
This material helps to fill the gap and reduce the amount of “melt
through”. Put a bit of masking tape on the top surface of the gap
and turn the panel over.
Solder
the back first. You can do this with 50/50 or 40/60 solder as it does
not change from solid to liquid and back so quickly as 60/40. However
the masking tape will keep the solder from dripping through if you
apply too much heat. When you have finished soldering the back, apply
masking tape to the now filled gap and turn over.
When
completing the soldering of the top, you will need to take care to
avoid over-heating the solder filling the gap. Over heating will
allow the solder to melt through the existing solder and flow along
the back. Usually, an application of dots of solder next to each
other avoids transmitting as much heat as running a bead will. When
you have passed the gap area, you can continue running the bead in
the normal way.
Gaps
between pieces
When
you have gaps between glass that cannot be cut or re-cut, such as
between globs, fill the gap with a piece of lead or copper foil sheet
cut to the size and shape of the gap. This is better than folded up
pieces of lead or foil as it carries the solder over the gaps to the
foiled pieces of glass. It allows for a smoother surface, and uses
less solder.
Note:
Remember
to avoid moving the panel for a while, as the large solder bead will
require longer to become solid, whether along a bead or filling gaps.
Glass
Breaking While Soldering
Some
report breaking pieces of glass while soldering. This may happen more
on pieces that have big differences in width or taper to thin points.
What is happening is that the glass is being heated too much locally
in relation to the rest of the piece.
The
solution is to solder at a steady pace. This allows the solder to
cool without transferring so much heat to the glass as to break it.
Some recommend that you do not rest your soldering iron on the foil
while soldering. However it is the solder which is the heat sink, so
the effort of holding the iron above the foil is not really necessary
if you move at a reasonable pace. This means that you do not stop
with the iron on the seam. It is best to solder in one continuous
movement along the seam, leaving an even bead behind.
Sometimes
the bead is not even. This may be because of wider parts to the seam,
or inadequate flux, or many other reasons. Do not try to repair this
before going on to the rest of the seam as this builds up heat in the
adjoining glass. Since glass cannot dissipate heat well, the glass
breaks when the temperature differential between the hot and cold
parts of the glass is too great. Instead, complete the soldering of
the seam before coming back to it. This gives you time to decide why
the bead is not as good as you want it to be. It also gives time for
the heat to even out through the piece of glass.
As
you become experienced you will find a pace that suits the kind of
bead on the joint that you want to achieve. If the seam is too flat,
slow your pace or increase the rate at which add the solder to the
iron. If the seam has too big a bead, increase your pace or reduce
the rate at which you feed the solder. It is also possible to
consider other methods of soldering ad described earlier.
You
also need consider the usual problems relating to cleanliness and insufficient flux as noted above.
Sometimes the soldering iron is not hot enough, but you should notice
this early as the solder will not be melting at its usual rate and
will be grainy in appearance.
Foil
not sticking on edge
The adhesive is an impact type that requires a smooth, clean and dry surface to stick well. The foil sticks to cleanly broken edges better than to ground edges. So ground edges need to be thoroughly cleaned before foiling.
The adhesive is an impact type that requires a smooth, clean and dry surface to stick well. The foil sticks to cleanly broken edges better than to ground edges. So ground edges need to be thoroughly cleaned before foiling.
The
adhesive on copper foil tape is not a permanent one. It only sticks
to the glass long enough to apply the solder to the foil. The heat of
soldering often degrades the adhesive so much that it no longer
sticks. What holds the solder down is the solder bead. So if the foil
lifts, you probably do not have a full bead on the edge. Placing a
bead on the edges of pieces is difficult but a method is given above
in the section "even solder beads on edges”.
You
can make the edge beading a bit easier by putting thin copper wire
around the edge of the piece. This also strengthens the whole piece.
It allows you to attach a hanger without risk of pulling the whole
sun catcher apart. It also allows you to form a bead on the edge more
easily.
The
bead formed on the edge curves around to the front and back faces
allowing the solder to hold the copper tape more firmly to the glass.
Bubbles
in the bead
Bubbles
appearing in the bead, or more dramatically, flux bursting through
the molten solder is most often the consequence of applying too much flux. Flux
should be only a thin film whether paste or liquid. To reduce this
boiling effect, reduce the amount of flux used and make sure all the materials are clean and free of oxidisation.
Other articles in this series are:
Processes
Materials
Tools
Other articles in this series are:
Processes
Materials
Tools
You mention using wire to go around the whole piece to give a better bead and strength. What size wire do you use?
ReplyDeleteA great informative article! Thank you for sharing. picking the top soldering flux.
ReplyDelete