Paraloid B-72

https://en.wikipedia.org/wiki/Paraloid_B-72

by Ariarule • 3 months ago

286 64 3 months ago

en.wikipedia.org

0xbadcafebee2• 3 months ago

Huh. So it's a stronger, harder, less brittle, clear wood glue you can dissolve with acetone. Neat!

zdw• 3 months ago

This is the most esoteric post I've seen on HN in a while.

How many museum curators who need non-yellowing flexible thermoplastic are there on here?

kazin1870• 3 months ago

I use paraloid all the time, a bit surprised to see it posted here but I’ll support it.

boppo14• 3 months ago

I'm new to it and having trouble finding guides:

- how do I apply it as a coating? I want it to be ~ 1/6" to 1/8" thick and as hard as possible

- will turpentine dissolve or soften it?

boppo14• 3 months ago

Oil painter here, this is news to me and if it doesn't dissolve in gamsol this is EXACTLY what I've been looking for for about 2 years.

card_zero• 3 months ago

I followed the link to flexographic ink, and now I'm wondering whether boutique fine art flexography could or should exist. Like lithography, but more plastic.

bfivyvysj2• 3 months ago

What's the application?

colordrops• 3 months ago

They should make non-yellowing transparent phone cases out of this stuff.

CarVac3• 3 months ago

I've done some DIY piano maintenance and I saw what was presumably this available to firm up the hammers. My piano needs them softened, though.

clort2• 3 months ago

Yes it mentioned firming piano hammers in the article. From what I remember, a piano hammer is a shaped piece of wood (or several?) with a leather strip around the striker part? What is the difference for you between hardening and softening the hammer, and how would it be done with this .. is it penetrating? (acetone base would enable that, it is used for carrying chemicals through a surface). Could you soften the hammers by replacing the leather strips, or soaking them to loosen & expand the presumably compacted fibres?

In my wider life in the UK, speaking to people associated with pianos (from a piano tuner, to school premises teams), it is often not worth the commercial expense to repair old pianos unless they are of particularly good quality or have some sentimental value.

aejm• 3 months ago

This post has exactly zero relevance to my professional career or personal projects, and this is exactly the type of esoteric content I love about HN!

uxhacker4• 3 months ago

The issue is that it does yellow but after 25 to 50 years. The challange is that it is very difficult to reverse.

On the restoration of my house I allow its use on very specific cases. It very useful for example in strengthening wood that has rotten. Sometimes Paraloid is the only thing that can be used, but it needs to be used with care.

uxhacker4• 3 months ago

You can see the research here : https://www.woodresearch.sk/wr/201104/07.pdf?utm_source=chat... and here https://www.researchgate.net/publication/400226168_Aging_Mec...

greygood2• 3 months ago

It does not turn yellow, Paraloid B66 does. B72 has a low Tg, 40°C, so it can soften and creep when warm

lollapalooza2• 3 months ago

Agreed. My gf uses it regularly as she's a furniture restorer, finding the definition here it's a bit of a surprise, though. Great, unique material.

glimshe• 3 months ago

Not many, but there are a few amateur and professional musicians here benefitting from better piano hammers made possible by Paraloid B-72!

Note: I thought this was about Polaroid, not Paraloid, at first!

nmstoker• 3 months ago

Yes, but that esoteric nature is the charm of HN at its best.

This is unusual as posts go, but it's not totally unreasonable and even though I wouldn't have an immediate use, it's fascinating, leads to further exploration (like another commenter mentioning the inks) and knowledge gets filed away.

I try to remember posts like this when people are less positive about HN! :-)

Eduard• 3 months ago

I'm especially curious about the high upvote count, considering the Wikipedia article as well as the substance in general is not that interesting IMHO.

idiotsecant• 3 months ago

The high number of upvotes is the same phenomenon as the comment chain full of people patting themselves on the back for enjoying estoteric content on HN. They didn't read it, they just like to imagine themselves as the sort of person who would read it. They probably have an apartment with a shelf full of curated tastefully selected novels that were purchased used for the proper patina and arranged just so, and then forgotten until it's time to subtly attract their guests attention to how clever they are. They probably have a couple Hemingway references they have memorized and bring out when the time is right.

Avshalom3• 3 months ago

Paleontologist and probably going to be doing pre-museum prep for some stuff here in the fall.

Although we're cheap so we usually use butvar (polyvinyl butyral).

rbanffy• 3 months ago

As someone who repairs and collects old computers, it might be one more tool.

FpUser• 3 months ago

Am I the only one that read it as Polaroid ;) ?

UncleOxidant• 3 months ago

No,you are not. I was expecting it to be a camera.

zephen• 3 months ago

I thought it was a cross between a camera and a bomber.

tgrowazay• 3 months ago

Polaroid for B-72 bomber

perilunar• 3 months ago

I thought it was going to be about a bomber with a parabolic-shaped wing, or something similar.

adrianmonk• 3 months ago

I read it as "paraboloid" and expected it to be about some very specific geometrical shape with a niche practical application.

aidenn0• 3 months ago

How does its strength compare to MMA structural adhesives? What materials is it compatible with?

shermantanktop• 3 months ago

My only expansion for MMA is “mixed martial arts” and I’m not particularly familiar with it. Maybe there’s a wrestling move called the “structural adhesive”?

clort2• 3 months ago

methmethacrylate (ie acrylic)

CarVac3• 3 months ago

Heh, I upvoted this a few days ago and it must've gotten on the second-chance queue.

Links to obsure but interesting Wikipedia articles are some of my favorite HN posts.

robotnikman• 3 months ago

This is one of my favorite ones, just because of how crazy of an idea it was, as well as the fact it was deemed possible to build

https://en.wikipedia.org/wiki/Lockheed_CL-1201

EdwardDiego• 3 months ago

Looking at that just screamed "coolest GI Joe vehicle that one rich kid at your school had and never let you play with".

Xmd5a• 3 months ago

Could this be used to 3D print supports ? For now, the only thermoplastic I know of that can be used to this effect is HIPS in conjunction with d-limonene.

a3w• 3 months ago

PVA also exists, solves in pure water.

mooman2192• 3 months ago

Oh I've used this personally! I had various surgeries that removed various amounts of bone from me and I asked to keep the bones, which they allowed! I wanted to preserve them in case I wanted to make some esoteric jewelry and it lead to paraloid B-72.

It's quite wonderful. I dissolve the paraloid B-72 in acetone (1 part B-72, 8 parts acetone), then soak the bone in the acetone for about an hour, let the bones dry, and then suddenly they're solid and strong. You can adjust how much acetone you use for how thin/thick you want the fluid. Bones are porus so I opted for a thinner solution and it worked great. It was also really cheap.

stavros2• 3 months ago

Hmm, what, the acetone evaporates and leaves just the plastic? Is that how it works?

0xbadcafebee2• 3 months ago

And typically penetrates into the material (https://rhadhesives.com/why-chose-solvent-based-adhesives/).

Adhesives are a deep and interesting subject if you're looking for a wikipedia hole. For example, if you want the best general-purpose consumer structural adhesive, it's Loctite PL Premium MAX. For the best general-purpose consumer structural adhesive applied in wide temperature ranges, it's Liquid Nails Fuze-It MAX. If you want the best flexible general-purpose consumer structural adhesive, it's Gorilla Heavy Duty Construction Adhesive. For the best all-purpose consumer structural adhesive when properly prepared, applied and cured, it's epoxy resin. For the strongest general-purpose adhesive when tightly fitted and clamped between two porous materials, it's cross-linked PVA (wood glue). There are dozens of variables that change which adhesive is better per application.

Avshalom3• 3 months ago

Yeah, the great part is you can then use fresh acetone to dissolve it. We do it with fossils all the time: glue it together, thin coat of glue all over then wrap and transport. Comes off easy in the lab.

gbgarbeb2• 3 months ago

Can we see the bones, Mr./Mrs. Bones?

mooman2192• 3 months ago

Sure, here are some photos https://imgur.com/a/iPDdmDP

webprofusion• 3 months ago

What we really need is a wipe on self leveling version. Finishing guitars is hard!

Isamu• 3 months ago

More posts please relating to conservator tech or websites. Thanks.

cmpalmer52• 3 months ago

Would this work for fragile shells and things like sand dollar “skeletons”? I usually use thinned white glue, but it’s less than ideal.

Avshalom3• 3 months ago

Yes this is exactly what we use it for.

Paraloid B-72

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