I recently received a Maury A027A SMA gage kit. Unfortunately, the gage mating surfaces did not have protective caps over them and the foam apparently degraded, leaving residue on the mating surfaces. The foam was replaced when I received it, but the residue is still there. I would expect the foam material is polyurethane, which is a common choice for these sorts of things and degrades over time. However, I can't be sure.
Any recommendations as to how to clean this? I've attached an image showing the mating surface of one gage. This is one of the worst ones, but the rest are similar. Normally, I'd use a fine-tip q-tip with some IPA. But, I'm not sure that's small enough and I'm also not sure it will remove residue that's probably gotten into the space between the sliding mechanisms. I've also thought about standing it upright (mating surface down) and soaking the end in some sort of solvent. I could try IPA, though it may not be effective enough. Another option is naphtha, which I believe should be effective on the residue and safe on the metal surfaces. I wouldn't want that to get residue further up into the sliding mechanism. Or, having the naphtha remain in those tight spaces. Are those risks? Thoughts on this solution? Other thoughts?
I tried blowing it out with an air compressor, but the substance is too sticky and won't budge.
If it's not easy to clean, I can return this for a refund. But, if I mess it up, I'll lose that right. So, I'd prefer not to try anything that is unlikely to work or could cause damage.
It is a mechanical device. You can probably dismantle the front part from the dial. These kind of dials are used in mechanical shops with all sorts of attachments.
As a 'stick' you can use dry wood. Easy to cut at any dimension. Think toothpick with a thin piece of cloth.
Avoid using anything metallic, you will scratch the surfaces
Any chemical needs time to act, some are quick some are slower. When you apply IPA give it a minute. Apply more if it dries up and you're not done cleaning. Use a squeeze bottle with fine nozzle with IPA to rinse the residue.
Distilled water kan help rinsing and is very cheap so you can apply it in big quantities. Rinse the water with IPA