Soldering

[Gepetto]

An educated guess is conformal coating Larry. A varnish like substance that is applied after component assy and wave solder. A photo of the component side of the board will help clinch that. I notice the darker green manually applied conformal coat added to the manually assembled (post coating) components that can be observed on the left side of the board photo. The conformal coating is solvent proof so will not be touched by ordinary solvents. An xacto knife and careful scraping of the coating off the pad is required to make solder adhere. Try it on one of the larger, less delicate pads so you don't further damage the board.

 

[speakerman1]

Thank you

 

[Gepetto]

Nice looking board, you do not want to damage that one. BTW, I hate conformal coating.

 

[speakerman1]

Could I acid etch it to remove the coating? If so what acid would I use. I am more comfortable doing that then scrapping.

 

[speakerman1]

OK I found that this stuff should remove the coating. methylene chloride So I am going to try this before I start scrapping.

 

[orange]

That's NASTY STUFF. Larrt! Defcon One, EPA love triangle stuff.

 

[speakerman1]

That is nothing compared with the stuff I used working on aircraft.

 

[NavLinear]

Larry,

We used to use chlorofluorocarbon (freon) and trichloroethane 111 to clean our printed circuit boards. The solvents would remove conformal coating quite well. We presently use a product named EnSolv - a vapor degreaser and cleaning solvent made by Enviro Tech International.

http://www.envirotechint.com/products/aerospace/

That green stuff Joe pointrd out on the left side of your photo sure looks like some sort of solder mask repair coating but I have seen coloration in conformal coating in the past. Some of the solder mask repair coatings are epoxy based so that could be tough to get off.

One other thought for a solvent would be acetone. Be careful with any of the solvents as some such as acetone can also remove component markings or damage the wrap on the electrolitics.

Good luck

 

[speakerman1]

John showed me this.

http://www.zorotools.com/g/00091033...ium=cpc&utm_campaign=Google_Shopping_Feed&kw=

 

[NavLinear]

That sounds like a good solvent. Are you going to try it?

 

[speakerman1]

Yes the pen will work good for what I want to do.

 

[speakerman1]

Thanks guys for all your help.

 

[Gepetto]

If you use the methylene chloride, do not use it anywhere indoors. It has more red alerts than just about any other solvent.

 

[speakerman1]

I thought I had paint stripper. I didn't. Some strippers has it in them. My liver is probably so messed up from beer and MEK that it is a wonder it works. I forget what we used the tric for. We went to a water based primer and it would freeze up when we used Prevals so instead of water we used MEK. LOL Dried fast and didn't freeze. Oh we used tric to reactivate the 1300L glue when gluing deice boots on. Some of that stuff will eat surgical gloves right off your hands.

 

[laatsch55]

No wonder your nuts!!

 

[laatsch55]

John told me to follow the traces and see if I can solder the leads to another solder pad and do that. LOL I got mad and threw my last 100K some where. LOL

Even I wouldn't throw my last100 grand around.

 

[Gepetto]

The secret is in the airplane glue

 

[speakerman1]

The secret is in the airplane glue

You got that right. LMBO

 

[laatsch55]

LMOAO!!!!!!!

 

[speakerman1]

It is getting there. I clean try to solder. Stuff weeps out of the board when I throw heat to it. So I heat and clean. The solder is starting to stick. Or should I say tring to stick. LOL Laughing a lot must be the fumes. LOLOLOLOL