HP probe boxes foam melt corode nasty, solution anyone ? - Page 1
Forum section: electronics / projects

author: oz2cpu
author_rank: Frequent Contributor
timestamp: October 29, 2023, 09:47:23 pm
content: I just show a little bit of the small items from some of my old HP probe and accessories boxes,the problem is the foam in the boxes often melt and turn into nasty slimy stickyand coroding stuff..,anyoen found a magic solution ?

author: helius
author_rank: Super Contributor
timestamp: October 29, 2023, 10:04:04 pm
content: The solution is throwing the old foam away and replacing it. As for cleaning the residue from the probes, your main concern is not to spread liquified plastic further. So a solvent that easily removes the foam residue could make the situation even worse, as it would wick over the probes and resolidify.I would probably use "Heavy Duty Flux Remover 413B" from MG Chemicals, and use a wet-dry towel technique. Moisten a section of one shop towel with solvent, rub the probes (understanding that it can remove paint or labels), then immediately dry with a second towel to prevent resin from redepositing. The most active solvent in the flux remover is acetone.

author: Stray Electron
author_rank: Super Contributor
timestamp: October 29, 2023, 11:12:15 pm
content: This is a well known problem and has been discussed on here before. But AFIK there's no way to undo the damage once it has occurred.

author: amyk
author_rank: Super Contributor
timestamp: October 30, 2023, 12:42:33 am
content: I suspect they were polyurethane foam, which degrades acidically in the presence of moisture. You can look online for articles about their decomposition products.I recommend replacing PU foam with PE foam as the latter will not degrade in the same way.

author: oz2cpu
author_rank: Frequent Contributor
timestamp: October 30, 2023, 08:02:45 pm
content: it is another sad day, i was inside all my HP probe and accessories boxes, all melted into total splat and sticky slime,its melted parts also caused bad corosion to paint and metal parts,it looks like it is alcohol and hard work that takes it away,I got two HP 1120A 500MHz probes with amplifiers all damaged too, darn it..I spent all night trying to get the amplifiers back into an ok state,I'll be back..

author: Bud
author_rank: Super Contributor
timestamp: October 30, 2023, 08:30:35 pm
content: I cleaned that stuff with mineral spirits. Not sure what equivalent product may exist in your country.

author: oz2cpu
author_rank: Frequent Contributor
timestamp: November 01, 2023, 09:18:32 pm
content: yes bud, IPA or just cleaning alcohol is easy to get,I am able to clean some parts into ok condition,but the boxes are just terible dont know if I just toss them, or try clean themthe smell is bad too, dont even want them inside, maybe I should share a picture ?

author: Bud
author_rank: Super Contributor
timestamp: November 02, 2023, 04:50:34 am
content: Mineral spirits is not IPA, it is a different petrolium-based product.I soaked the foam gunk inside the box with mineral spirits and scraped off with an old credit card.

author: helius
author_rank: Super Contributor
timestamp: November 02, 2023, 07:33:49 pm
content: Mineral spirits are called "benzin" in many non-English languages. In French it is "l'essence minérale". It is non-polar and thereby more effective at dissolving adhesives. A similar product is naphtha, or "nafta" or "neft".It is also very similar to oil painters' "odorless" solvent, known informally as "turps".

author: oz2cpu
author_rank: Frequent Contributor
timestamp: November 03, 2023, 03:39:16 pm
content: thanks a lot helius for the name explainI also got that stocked, I will make a little benchmark comparewhat works best