I have successfully used hot-melt for restraining large surface mount electrolytic capacitors. That was done using industrial high-temperature hot-melt. I would avoid normal consumer high-temp hot-melt since it softens at temperatures well below +85C (industrial temperature ranges) Mike -----Original Message----- From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of Dwayne Reid Sent: Thursday, January 31, 2019 12:00 To: Microcontroller discussion list - Public. Subject: Re: [EE]:: Hotmelt adhesive for heavy component retention Hi there, Russell. I have used Holt Melt Adhesive to hold heavy objects with varying degrees o= f success. The old 'original' holt-melt is not good for long-term use. I'm talking about the glue from 30 or 40 years ago (I still have some ). The problem with this glue is that it is hard and not flexible. The modern cheap Chinese-made hot-melt from from Dollar Stores is actually not bad. It is much softer and more flexible. It also seems to hold better. As has been mentioned by others: applying the glue to something that is war= m or hot gives much better adhesion. One interesting use of holt melt for me is to use it as a moldable form for irregularly-shaped objects. I'm mostly talking about large cylindrical electrolytic capacitors. What I do is attach the object with hot-melt glue and ensure the voids are completely filled. Then I break the glue free fro= m both the object and the surface that I'm attaching to. This is most easily done by putting everything into the refrigerator. Then smack the capacitor with a sharp blow, then the block of hot-melt. The block of hot-melt breaks free quite easily. But: now I have a perfect spacer that fits both the surface and the object. Now, I simply glue everything back in place using cyanoacrylate (super glue). This works very well - I'm pretty sure that I still have stuff mounted this way after decades of use. Unfortunately, I don't have any long-term data for the modern (softer) hot-melt glue. But you may want to consider the technique that I mentioned above. dwayne At 03:52 AM 1/31/2019, RussellMc wrote: >Short: Does anyone successfully use hot-melt adhesives to retain=20 >larger components in place mechanically, with no bond failures over=20 >lifetimes of many years? If so, please comment. > >Longer: > >At various times we have had discussions on the PICList re the use of=20 >adhesives to help locate / retain ... heavy components on PCBs. > >Here and in other forums I have resolutely insisted (eg *here >* & *here >)* that using=20 >hot-melt adhesive is an invitation to disaster as it does not retain=20 >its bond long term. While this has been my observation in all cases=20 >where I have encountered its use by others, this is clearly 'selling it=20 >short" by using the term HM for a vast range of products, some of which=20 >SHOULD be eminently suitable for the task. > >A quickish web search turned up dozens of(apparently) good quality=20 >references to HM and a large range of technical literature. > >It seems 'obvious' that SOME hot melt adhesives would do a good job of=20 >the 'simple' task of retaining a largish component in place=20 >indefinitely, and not losing bond strength weeks months or even years thereafter. > >So - again: Does anyone successfully use hotmelt adhesives to retain=20 >larger components in place mechanically, with no bond failures over=20 >lifetimes of many years? If so, please comment. >Brand, type, application results, ... . > > > > Russell > >_________________________________________ > >https://www.bond-tech-industries.com/about-us/blog/6-reasons-hot-melt-a >dhesive-isnt-working/ > >https://multimedia.3m.com/mws/media/39803O/used-to-rigidize-large-compo >nents-on-cicuit-board-of-dryer.pdf?fbclid=3DIwAR0KtAAUx9VCbIDyQ7moNGGKMnF >mmiAJvIIfD5FEBSjxkoQYIHqJf5jAskg > > >https://multimedia.3m.com/mws/media/1245163O/3m-hot-melt-adhesive-3764- >3748-technical-data-sheet.pdf > >https://www.tandfonline.com/doi/abs/10.1080/00218469708010513https://wi >ki2.org/en/Hot-melt_adhesive > >https://www.intemag.com/images/uploads/Loctite_Hot_Melt_Technology.pdf > >https://intactadhesives.com/products/adhesives/ > >http://www.siegeladhesives.com/heatspek-technology > > >https://www.google.com/search?q=3D3M%E2%84%A2+Scotch-Weld%E2%84%A2+Hot+Me >lt+Adhesive+3748&oq=3D3M%E2%84%A2+Scotch-Weld%E2%84%A2+Hot+Melt+Adhesive+ >3748&aqs=3Dchrome..69i57j0l2.1453j0j8&sourceid=3Dchrome&ie=3DUTF-8 > >http://siegeladhesives.com/industrial-assembly/ > >*A nice 3M adhesive guide- HM & much more* > > >https://multimedia.3m.com/mws/media/372489O/adhesives-and-tapes-design- >guide.pdf > > >http://multimedia.3m.com/mws/media/44021O/3m-hot-melt-bonding-systems-g >uide.pdf > >https://www.google.co.nz/search?num=3D40&q=3Dhot+melt+adhesive+bond+failur= e >&tbm=3Disch&source=3Duniv&sa=3DX&ved=3D2ahUKEwj87eGrppXgAhUxKX0KHSFeDSoQsA= R6BAg >DEAE&biw=3D1602&bih=3D899 > >https://www.bostik-industrial.com/consider-automotive-hot-melt-adhesive >s-car-assembly/ >-- >http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive=20 >View/change your membership options at=20 >http://mailman.mit.edu/mailman/listinfo/piclist --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA 780-489-3199 voice 780-487-6397 fax 888-489-3199 Toll Free www.trinity-electronics.com Custom Electronics Design and Manufacturing -- http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/chang= e your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .