Not a "Classic" Checkerboard Issue

[Alex]

Yea you have a point there. Mine is well water, not city. So could be different. 

I should be cleaning my mother boards with well water myself, we have both city and well here as well. I know the water is very clean, I drink it often and it really is amazing. I will continue to use DI because I just don't know how to test any water for contaminates, ions or ohms, but yeah, thanks for pointing that out. Very interesting indeed!

 

[techknight]

With ultrasonic cleaning I do at work, I keep it all distilled in the cleaning pot with the cleaner. 

I still rinse it off with tap water, but I quickly displace the water with a bucket of 90% alcohol so the oxidation from the minerals cannot setup. I do this extra step so the alcohol doesnt get saturated with flux and cleaner causing streaks, etc. 

I then bake it. 

all my boards come out squeeky clean. 

 

[Alex]

With ultrasonic cleaning I do at work, I keep it all distilled in the cleaning pot with the cleaner. 

I still rinse it off with tap water, but I quickly displace the water with a bucket of 90% alcohol so the oxidation from the minerals cannot setup. I do this extra step so the alcohol doesnt get saturated with flux and cleaner causing streaks, etc. 

I then bake it. 

all my boards come out squeeky clean. 

Sadly I don't have access to an ultrasonic cleaner. Yeah the isopropyl alcohol or similar is a great way to push the water off. In terms of baking, could you provide some details on temp. and duration?

 

[techknight]

Depends on the size of the board but I never go above 200. 

 

[Alex]

The plastics are the particular concern. What's the average time you bake them for? I have to start using the baking process myself. The idea of a super shiny clean board is very attractive.

 

[techknight]

if you dont go above 200 the plastic parts survive. its when you get higher than that is where problems are. 

a big IIx board would be around 15 minutes max. 

SE/30 could take around 10 to 12 or so. getting the liquid out of the ports and under the ICs take the longest. 

 

[Alex]

SE/30 could take around 10 to 12 or so. getting the liquid out of the ports and under the ICs take the longest. 

A good preflight before baking could be some canned air action I suppose. I really like the idea. Thank you for the exchange! I guess we better not hi-jack DistantStar001's original query any longer  

 

[techknight]

LOL.. yea. that tends to happen... alot... around here. 

 

[tanaquil]

Another board member recommended 175 (if I remember rightly) but turn the oven OFF before you put the board in and leave it for several hours. I did that with one set of boards and they came out fine. I don't have enough experience to 100% guarantee the method though.

@techknight, where do you buy your alcohol supply LOL? I'd like to use 90% isopropyl more liberally than I already do but the bottle I have (definitely not bucket size) cost a fair bit.

 

[techknight]

When I say bucket, I mean like a large cake tupperware type thing with a snap lid to prevent evaporation. 

We order wave soldering flux all the time, and it comes with the 4662 thinner, which is, yep, alcohol. 1 gallon. 

 

[just.in.time]

@DistantStar001 everyone has given some great advice here. Best of luck, should be fixable

. @techknight and @Alex I generally bake my boards at 160 (lowest my oven goes) for 45 minutes after cleaning. I also do a final rinse with 91% alcohol immediately before baking, so it should evaporate much faster than water anyways. Seems like everyone has their own variation of the process.