Putty to hold things in place while glue is setting - Page 1
Forum section: electronics / general

author: tchicago
author_rank: Regular Contributor
timestamp: May 03, 2025, 05:23:50 pm
content: I occasionally use epoxy and other glues to fix the broken plastic items. While the glue cures, the item needs to be fixed in place. Sometimes, the crack that is being repaired in such an inconvenient place, that there is no way I can use any kind of clamp to keep it in place. Some time ago, I saw someone on Youtube was using some hand-malleable sticky putty to temporarily hold things in place. I did not notice what was the name of that material.Does anyone know what this could be? The children's play putty is too oily, soft and not sticky enough. The Loctite "picture hanging putty" is too hard to mess into a proper shape, same problem with other brands of "picture hanging putty", like Elmer's etc.Just yesterday, I literally had to hold the Tektronix power switch lever in hands while it was curing

author: Stray Electron
author_rank: Super Contributor
timestamp: May 03, 2025, 07:11:35 pm
content: I've never used putty for that purpose but I sometimes use hot melt glue or super glue for a nearly instant fix. For porcelain i've also used clothes pins, rubber bands and the like to hold things in place while conventional white glue or wood glue dries.

author: Ian.M
author_rank: Super Contributor
timestamp: May 03, 2025, 08:49:09 pm
content: It may be worth experimenting with low temperature hand mouldable thermoplastic. e.g.https://www.adafruit.com/product/2504

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 03, 2025, 08:52:39 pm
content: UV Glue perhaps - sets in a couple of seconds when exposed to UV

author: MarkF
author_rank: Super Contributor
timestamp: May 03, 2025, 08:54:15 pm
content: Oh, you want "Silly Putty"!Be sure to get it in its original plastic egg...Seriously, you might "blu tack putty"Similar tohttps://www.staples.com/loctite-fun-tak-removable-adhesive-putty-2-oz-blue-1270884/product_1480018?gQT=1

author: coppercone2
author_rank: Super Contributor
timestamp: May 03, 2025, 08:57:40 pm
content: There is UV cure putty. I never used it. I don't like UV glue. But if the putty works it has merit

author: Gregg
author_rank: Super Contributor
timestamp: May 03, 2025, 09:00:58 pm
content: Bostick brand "Blu Tack"

author: dferyance
author_rank: Regular Contributor
timestamp: May 03, 2025, 09:04:03 pm
content: Check out Rodico putty. It is sticky, but not sticky enough to be difficult to remove cleanly. Watchmakers use it for cleaning, gripping parts and holding things. I'd only suggest it for small parts though, it isn't going to be either sticky or stiff enough for something large.

author: BrianHG
author_rank: Super Contributor
timestamp: May 03, 2025, 10:41:54 pm
content: Have you considered optically cured epoxy instead.Place the epoxy glue on the item.Hold in place.Turn on blue led curing flashlight, and within a second, hard as a rock.

author: Psi
author_rank: Super Contributor
timestamp: May 03, 2025, 11:25:39 pm
content: A 405nm laser pointer works well for setting UV stuff and are easy/cheap to buy.Maybe not the 1mW ones, but you can find 15mW-50mW ones pretty easy. Just be careful with them, they're a lot brighter than they seem to your eyes.Failing that you can get UV LED emitters pretty cheaply, but because they're more of a UV flood light they can be more dangerous than a pointer you can easily control. And some of them are a lot deeper into the UV spectrum as well. high power UVC is scary etc.. 405nm is safer if a bit slower.Production lines often use high power UV diodes with a fiber optical cable wand. Very rapid UV glue set but basically a cancer gun.

author: Someone
author_rank: Super Contributor
timestamp: May 03, 2025, 11:42:18 pm
content: Quote from: Psi on May 03, 2025, 11:25:39 pmPossession and import both being illegal in Aus and NZ.

author: Psi
author_rank: Super Contributor
timestamp: May 04, 2025, 03:12:05 am
content: Quote from: Someone on May 03, 2025, 11:42:18 pmHence the comment to be careful.

author: Smokey
author_rank: Super Contributor
timestamp: May 04, 2025, 10:27:49 am
content: If you've never worked with super glue accelerator (or baking soda), its pretty amazing stuff.

author: tchicago
author_rank: Regular Contributor
timestamp: May 04, 2025, 02:25:40 pm
content: Thanks everyone for suggestions!- First thing, I'll try to get that Blu-Tac stuff first, and Loctite too. Thanks! (I only tried one type of Loctite, that was way too stiff for the purpose, did not realize there were other ones)- Regarding the UV-curing epoxies, could someone please recommend a reasonable brand/type and a source of it? I only saw a recommendation for RELIFE RL-35D from Aliexpress, but they don't ship to U.S. anymore likely due to tariffs. (Also, I don't need a 15-liter canister of it, likely available from various U.S. industrial suppliers).I do have a high-power UV emitter though - for the occasional PCB solder mask repair. The problem I have with the UV-curing solder mask liquid is that no matter how powerful the UV source is, if the layer of liquid is just a little too thick, it remains liquid underneath the thin top surface that hardens. I.e. the UV does not penetrate deep enough to cure the whole thing solid, no matter how long the exposure is. Does the UV-curing epoxy have same problem?- Suggestion to use the super glue with accelerators: I avoid it because it is too brittle, not suitable where the mechanical strength is needed. Also, the super-glue evaporates, leaving an uncleanable white residue highly visible on nearby surfaces (especially bad for acrylic)BTW, I found a useful general rule of thumb regarding the classic 2-component epoxy resins: the longer the curing time, the higher mechanical strength. It is clear even from the manufacturer specs.

author: coppercone2
author_rank: Super Contributor
timestamp: May 04, 2025, 07:02:09 pm
content: Well I was facinated by this, and researched glues.it basically looks like the strength of a single part UV resin is approx 55% as strong as a 2 part epoxy for tensile strength (in scenarios involving glass).Long cure epoxy is stronger, lasts longer, and you can make it more forgiving to use by using a 'non sag' version that has additives which make it more gel like (less droop), but it won't cure faster unless you use a oven.However theoretically you do have UV cure epoxies which could be UV activated but also have a very long cure time. The UV breaks down the molecules into reactive ones that start a reaction in the glue. So I believe you could make theoretically a 1 minute set UV epoxy or a 48 hour set UV epoxy (which requires some activating time, but it will be fully activated and still not cured, because the UV is not curing it, its just making a chemical that can cure it). Not sure what the market for this product would be, perhaps a very long pot life.14 day cure timehttps://www.3m.com/3M/en_US/p/d/b40066476/

author: u666sa
author_rank: Frequent Contributor
timestamp: May 04, 2025, 11:27:18 pm
content: Plastelinehttps://www.amazon.com/Chavant-Professional-Plasteline-Lb-Brown/dp/B079YYHZWR