Chemical question
2017-08-27 by Technotronic~Dimensions
Saw some videos on what looks like an LCD type of chemical that changes color with temperature. Im looking to experiment with some chemicals that change color
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Re: CNC PCB mill...
2017-08-20 by Peter Tremewen
Hi all, Thanks for the help and info... Will look into it a bit further and decid if it s for me... Peter T.
Re: [Homebrew_PCBs] CNC PCB mill...
2017-08-13 by Art Eckstein
I occasionally do a one off for my hobby experimentation using a homebuilt moving table router. The spindle is a 70 watt max 30,000 rpm unit. I usually use
Re: [Homebrew_PCBs] CNC PCB mill...
2017-08-13 by Boots Hughston
I have been using CNC engraver/ router for over 10 years. They are not perfect and take some getting use to. Get one the can do at least12 sq. The higher
RE: [Homebrew_PCBs] CNC PCB mill...
2017-08-13 by Bertho
Peter, I do not think that is cost-effective today. Your time and effort plus the cost of a good CNC engraver is significant. Regardless, the result is not
CNC PCB mill...
2017-08-13 by Peter Tremewen
Hi All, I am considering buying a CNC engraver to manufacture protype PCBs on.. Just wondering What experiance everyone has with this... Any information
Re: [Homebrew_PCBs] White TRF Clearcoat
2017-08-10 by Harvey White
... It depends on the board and which layers you use to print the silk screen. Nail polish is fine, you might want to thin it, though, or use a thin coil dope
Re: [Homebrew_PCBs] White TRF Clearcoat
2017-08-10 by alan00463@...
Thank you for your comments. Well, Harvey, covering the pads would be an issue for a SMT board, yes. That is what made me think of using nail polish---it
RE: [Homebrew_PCBs] White TRF Clearcoat
2017-08-10 by keith printy
I would think the coating is thin enough to just solder right through it. I ve dealt with boards with a coating like that and was able to solder through From:
Re: [Homebrew_PCBs] White TRF Clearcoat
2017-08-10 by duwaynes@...
For boards that I am not going to tin, I polish the copper real well and give a light coat of Krylon. Have had no problems soldering right through the Krylon,
Re: [Homebrew_PCBs] White TRF Clearcoat
2017-08-10 by Harvey White
... Wouldn t covering the exposed pads be a problem? Harvey
RE: [Homebrew_PCBs] White TRF Clearcoat
2017-08-10 by keith printy
What about using clear krylon spray ? it applies like paint but puts a clear plastic coating on whatever you spray it. From: Homebrew_PCBs@yahoogroups.com
White TRF Clearcoat
2017-08-09 by alan00463@...
I am about to order White toner reactive foil to use as silkscreen (component outline). I was thinking about clearcoating the white-outlined component
RE: [Homebrew_PCBs] Re: Salt/Vinegar/Peroxide
2017-08-07 by Brad
Thanks!! It’s interesting how different combinations of the three components changes the way the etch process happens. If I go lighter on salt and more
Re: Salt/Vinegar/Peroxide
2017-08-03 by duwaynes@...
You can get much stronger HP at your local beauty supply store. It is labeled as developer and comes in different concentrations or volumes. 10 volume 3% 20
File - monthly.txt
2017-08-01 by Homebrew_PCBs@yahoogroups.com
Monthly Reminder for Homebrew_PCBs list, please read: Messages and threads: Please do NOT start a new thread by replying to another message. Even if you change
RE: [Homebrew_PCBs] Re: Attaching two PCBs together
2017-07-26 by Tony Smith
Never tried felt, anything like that should be fine. I ve seen people use mesh, like window mesh as well. Of course you need to make sure the epoxy squeeze
RE: [Homebrew_PCBs] Re: Attaching two PCBs together
2017-07-26 by Jeff Heiss
Felt works well to provide an air path in the bag. Without a porous material, the bag seals off at the vacuum tube connection preventing an evacuation. Try
RE: [Homebrew_PCBs] Re: Attaching two PCBs together
2017-07-26 by Tony Smith
You need a spacer between the boards and the bag, like Roy said in his last message. The PCB needs to go between two flat boards (solid) larger than them, then
RE: [Homebrew_PCBs] Attaching two PCBs together
2017-07-26 by roylowenthal@...
I just did the experiment - a shop vac pulls about 3 Hg vacuum. Interesting because I ve used it with a perforated board fixture to hold wooden things being
RE: [Homebrew_PCBs] Re: Attaching two PCBs together
2017-07-25 by Brad
Tried the vacuum bag method with a thick contractor garbage bag. It did pull the bag taut against the boards but also sucked the bag a good way into the shop
Re: [Homebrew_PCBs] Re: Attaching two PCBs together
2017-07-25 by Harvey White
... Yep. ... Nope. You create donuts around the feedthrough locations in the inner layer. However, you ve got no way of soldering them at all. Inside layers
Re: Attaching two PCBs together
2017-07-25 by Dave Sage
Dumb question: If the boards you are gluing together are single sided boards don t you end up with either a double sided board OR a single sided board with a
RE: [Homebrew_PCBs] Attaching two PCBs together
2017-07-25 by Jeff Heiss
An aquarium air pump also works as a vacuum pump. It pulls a higher vacuum than a shop vac, quieter, and more convenient. I use one for photoresist vacuum
RE: [Homebrew_PCBs] Attaching two PCBs together
2017-07-25 by roylowenthal@...
You really want to use a shop vac for that kind of work! Shop vacs have separate fans to keep the motor cooled while it s running - household vacs don t; they
RE: [Homebrew_PCBs] Attaching two PCBs together
2017-07-24 by mbushroe@...
There is a technique you can borrow from home built airplane builders. Vacuum bagging. Ideally, you would get the special perforated separator sheets, but you
RE: [Homebrew_PCBs] Attaching two PCBs together
2017-07-24 by Brad
I would be interested in anything that simplifies the process. I looked up Henkel online but didn’t see the paint-on stuff you were mentioning. Any leads
RE: [Homebrew_PCBs] Re: Attaching two PCBs together
2017-07-23 by K5ESS
You would have to find a way to maintain registration between the top and bottom and deal with the adhesive squeezed out in the process. From:
Re: Attaching two PCBs together
2017-07-23 by AncelB
Why don t you apply the chosen adhesive and run the thing thru a cold or warm paper laminator a few times. .
RE: [Homebrew_PCBs] Salt/Vinegar/Peroxide
2017-07-23 by dougholberg@...
http://www.ebay.com/itm/20pcs-1-25mm-Foam-Sponge-Brushes-Wooden-Handle-Painting-Drawing-Craft-Draw-/371515013455?hash=item568005394f
RE: [Homebrew_PCBs] Attaching two PCBs together
2017-07-22 by Howard Chester
Hello Brad,I have in the past used a 2 part adhesive from Hienkel. This method eliminates bubbles and high curing Tempratures Unlike epoxy, the 2 part
RE: [Homebrew_PCBs] Attaching two PCBs together
2017-07-22 by Andrew Volk
Brad û Two comments on vacuum. The key is the degree of vacuum you get is most important. Getting down to 20ö Hg is good. Also, you donÆt need a big
Re: [Homebrew_PCBs] Attaching two PCBs together
2017-07-22 by Harvey Altstadter
Brad, The vacuum press is not complicated. It is not really a press. We used a heavy duty silicone rubber bag that was designed for that purpose. I don t
RE: [Homebrew_PCBs] Attaching two PCBs together
2017-07-22 by Brad
Thanks for all the great responses. I guess I have a lot to think about now. A question about temps û do I need to worry about fire risk, etc doing things
RE: [Homebrew_PCBs] Attaching two PCBs together
2017-07-19 by Andrew Volk
Harvey, Brad û A PCB in a vacuum bag is getting about 15 lb. per square inch clamping just from atmospheric pressure and a consistent pressure across the
Re: [Homebrew_PCBs] Attaching two PCBs together
2017-07-19 by Harvey Altstadter
Brad, As Andrew V. mentioned, vacuum bagging is an effective process for laminating. There are a couple of issues when using epoxy, or any resin that requires
Re: [Homebrew_PCBs] Attaching two PCBs together
2017-07-19 by Harvey Altstadter
Jeff, I found prepreg on the manufacturer sites, but no where to actually buy it in small quantities. It makes sense because it is used in large sheets, not
RE: [Homebrew_PCBs] Attaching two PCBs together
2017-07-19 by Andrew Volk
Brad û Use a vacuum press. Vacuum is useful for many things, especially if you are also into woodworking (veneering), molding, etc. The vacuum will draw the
RE: [Homebrew_PCBs] Attaching two PCBs together
2017-07-19 by Jeff Heiss
The material used to glue layers together in multilayer boards is called prepreg. I donÆt see prepreg sold online anywhere though. Not even Ebay. From:
Re: [Homebrew_PCBs] Attaching two PCBs together
2017-07-18 by Harvey Altstadter
Brad, I think you slipped a decimal point o the thickness of your boards- 0.031 and 0.0625 . There is another (better?) way, but it is problematical. You would
RE: [Homebrew_PCBs] Salt/Vinegar/Peroxide
2017-07-18 by Brad
Sorry.. I meant to say ‘sponge’, not brush. From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] Sent: Tuesday, July 18, 2017 11:16
RE: [Homebrew_PCBs] Salt/Vinegar/Peroxide
2017-07-18 by Brad
I tried this when I got my first bottle of ferric. It didn’t work… it took half an hour of continuous scrubbing with the brush to get anything going…
Attaching two PCBs together
2017-07-18 by Brad
So as I stated in a previous post, I have acquired some vintage 1973 PCB stock, which is perfect for a project I m doing that replicates the 1973 TV
Re: Salt/Vinegar/Peroxide
2017-07-18 by Larry Battraw
I know the OP appears to be in Canada, however here in the US I recently found it s possible to buy 35% HP via Amazon, and I was able to get a quart of it
Re: [Homebrew_PCBs] Salt/Vinegar/Peroxide
2017-07-18 by Mitch Davis
Hello fellow home brewers, On Tue, Jul 18, 2017 at 2:26 AM, Brad unclefalter@yahoo.ca ... It is possible to etch very fast and very well if you use
Re: [Homebrew_PCBs] Salt/Vinegar/Peroxide
2017-07-17 by Norm
I m not a chemist - (College Chem101 in 1958). That s why I referenced the article - I ll see if I can find it again - might even be in the files in this
RE: [Homebrew_PCBs] Salt/Vinegar/Peroxide
2017-07-17 by Brad
Thanks Norm. Yeah, I m just reluctant about using actual HCl for the reasons you mentioned. I m generally pretty careful but I m also a bit accident prone and
Re: [Homebrew_PCBs] Salt/Vinegar/Peroxide
2017-07-17 by Norm
When you mix the salt (sodium chloride, NaCl) with vinegar (5% acetic acid, HAc), the result is weak homemade hydrochloric acid (HCl) and some leftovers.
Salt/Vinegar/Peroxide
2017-07-17 by Brad
I m trying to wrap my head around how this works, to better mix it. I actually like working with this method - the resulting etchant is way less unpleasant
Re: Vintage PCB toner transfer problems
2017-07-11 by mosaicmerc@...
Don: A lot can change in 20 years....and it has. have a look. https://hackaday.io/project/7938-pcb-smt-maker-lab-home