Does superglue and activator damage components? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: July 03, 2024, 06:34:57 pm
content: Hi,Just had to glue six thermocouples to heatsinks of fets and diodes on a multi SMPS PCB...used superglue and then sprayed with Loctite 7649 activiator.The activator sprays all over the place as we have no nozzle, and the superglue was dribbling all over the PCB abd over the components.Do you think we will get damage? (if it was left a long time)The superglue was "ultratape , ultrastick superglue"loctite 7649 activatorhttps://www.henkel-adhesives.com/us/en/product/adhesive-activators/loctite_sf_76490.209715.htmlUltratape supergluehttps://www.ebay.co.uk/itm/364696184045?mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338757644&toolid=20006&customid=cf3e6e357b8e9d3a63cc59794752f41b&_trkparms=ispr%3D1&amdata=enc%3A17A1YuI3bQCCVLDiHUxkVRg11

author: thm_w
author_rank: Super Contributor
timestamp: July 03, 2024, 09:28:00 pm
content: The activator solvent is acetone, so that could melt some weak plastics, but you'll clearly see, probably be fine for anything on a PCB.Activator active ingredients copper salt and Aliphatic amine. Maybe if it really did spray everywhere that would be concerning and should be cleaned off. But it seems quite thin?Cyanoacrylate glue should be safe for the PCB itself.In the future use the brush on activator version instead, or kapton tape.

author: Stray Electron
author_rank: Super Contributor
timestamp: July 03, 2024, 10:40:18 pm
content: I don't know if SG will damage components but I think that usually not. But I can't be sure that that's true of all materials. But what it will do is generate fumes that will condense on circuit boards, contacts, etc and will create a hard insulating layer or film on them. (Ask me how I know!) I set a fan nearby to draw the fumes away to prevent that from happening.A little story for you; the engineers at Martin Marietta in Orlando discovered that the SG fumes would condense on nearby surfaces and they noticed that the condensate film was VERY good at showing any finger prints on the surfaces. Someone told the Orlando Police Department about it and they started using that process to locate and highlight finger prints on just about any surface. That now seems to be the most common way that police and LE in the US are processing finger prints.

author: Andy Watson
author_rank: Super Contributor
timestamp: July 03, 2024, 10:49:22 pm
content: Doesn't consumer-grade superglue degrade at relatively low temperatures (sub 100C)? I would be more concerned about the thermocouples falling off when the fets warm-up.

author: Mr.B
author_rank: Unknown
timestamp: July 03, 2024, 10:52:46 pm
content: ^ This.I always use thermally conductive epoxy for these types of tests or studies.

author: jpanhalt
author_rank: Super Contributor
timestamp: July 04, 2024, 12:13:51 am
content: What's not clear is why you used an activator to promote anaerobic cure in an aerobic situation. (That activator contains a small amount of acid in acetone.) Metal oxides are basic. Anodized aluminum causes rapid cure. Curing is also promoted by water/humidity. Did you try the glue without activator? The acidic nature of that catalyst might actually have inhibited curing in air in your situation. Dusting the TC in baking soda, then shaking off all excess would have worked, if needed. Or, use a basic activator, if you really need one.Discussion of anionic (basic) and radical cure (anaerobic) mechanisms:https://www.mdpi.com/1420-3049/23/2/465Anaerobic adhesives:https://www.researchgate.net/publication/327597274_Mechanism_of_Initiation_of_the_Curing_of_Anaerobic_Adhesives