Adhesives for securing components - Page 1
Forum section: electronics / beginners

author: jpyerry
author_rank: Newbie
timestamp: January 10, 2013, 07:59:11 am
content: Hi guys! I am new here. Dave, if you are reading this, I love your show it is better than anything on regular TV! Keep up the good work.I have been doing some research on faulty capacitors and I have a computer power supply that has a few bulging capacitors on it and I want to try to repair it by replacing the electrolytic capacitors.Now for my question, I noticed a good deal of components have a creamy white opaque adhesive on them. In his videos Dave refers to it as selastic (not sure on the spelling), I have not been able to find it online. I wondering if anybody has any recommendations on what type of adhesive I should buy and where I can buy it. I live in the US, but I do most of my shopping online.Your help would be much appreciated!Yours,Justin

author: Fsck
author_rank: Super Contributor
timestamp: January 10, 2013, 08:03:54 am
content: It's a silicone adhesive I believe. Likehttp://canada.newark.com/gc-electronics/19-155/adhesive-silicone-tube-3fl-oz-us/dp/00Z1554?in_merch=Popular%20ProductsDave is talking about "Silastic"

author: TorqueRanger
author_rank: Frequent Contributor
timestamp: January 10, 2013, 09:17:13 am
content: Quote from: jpyerry on January 10, 2013, 07:59:11 amI am using a low wattage hot glue gun and never had any problems...

author: ftransform
author_rank: Frequent Contributor
timestamp: January 10, 2013, 10:07:04 am
content: what is shelf life of this stuff?

author: SeanB
author_rank: Super Contributor
timestamp: January 10, 2013, 10:25:06 am
content: Once opened very short. You need the electronics grade ones, not the bathroom sealer types. If it smells of vinegar it is definitely a no go item. Typically if sealed very well and stored in a refrigerated place with low humidity it will last between 6 months and a year. Water from the ambient air will cause it to cure.2 part flexible epoxies are a usable alternative, at least they last a long time if unmixed provided the caps are not mixed up and kept tight.

author: AndyC_772
author_rank: Super Contributor
timestamp: January 10, 2013, 10:40:35 am
content: I wouldn't even bother, unless the product is going to be subjected to vibration.

author: nukie
author_rank: Frequent Contributor
timestamp: January 10, 2013, 11:43:17 am
content: Neutral cure silicon works best but it isn't for electronics(inform me why not) its also cheap.Loctite Super Bonder is the stuff used for smt.

author: ftransform
author_rank: Frequent Contributor
timestamp: January 10, 2013, 02:14:26 pm
content: It would be nice to have but I can't justify buying a product with a low shelf life. Unless they sell it in single use mini ketchup style packets.

author: Alana
author_rank: Frequent Contributor
timestamp: January 10, 2013, 03:21:44 pm
content: Would hot glue work? Its quite OK if you are not trying to glue together parts that can heat up themselves.

author: SeanB
author_rank: Super Contributor
timestamp: January 10, 2013, 03:25:57 pm
content: Then just use the flexible 2 part epoxy. Cheap, long shelf life and has other uses as well.Hot glue is not recommended. Depending on how it is made and the formula used it can be quite corrosive, conductive and hygroscopic. No way to tell unless you test each batch for this. It is used a lot on boards but often you find it breaks loose with time.

author: nanofrog
author_rank: Super Contributor
timestamp: January 10, 2013, 08:47:37 pm
content: Quote from: SeanB on January 10, 2013, 03:25:57 pmThe stuff from local craft stores, you make a very valid point. Generally speaking though, Polyamide (good for potting), Polyurethane (staking components), and Polyolefin (high temp applications & hard to adhere components) have their uses. As per moisture, there are ways to store it that can prevent moisture absorption.If other products aren't feasible, the trick with glue sticks would be to buy from a known supplier IMHO, such as 3M or Power Adhesives (sold as TecBond), as they publish specification data. Here's an example of Tecbond 7718.http://www.farnell.com/datasheets/391838.pdfAnd of course, it's relatively inexpensive vs. other products, which might explain it's presence in electronics manufacturing.Something that definitely gets the bean counters attention.

author: jpyerry
author_rank: Newbie
timestamp: January 12, 2013, 12:39:55 am
content: Thanks guys, I will consider buying some of the items mentioned in your replies.Your help is appreciated!Yours,Justin

author: peter.mitchell
author_rank: Super Contributor
timestamp: January 17, 2013, 05:47:25 am
content: The main reason I don't use hot glue is in its name, it melts when it gets hot. Often it will "reform" itself if it is in a warm environment, making it entirely useless.

author: Rick
author_rank: Frequent Contributor
timestamp: January 17, 2013, 08:30:54 am
content: http://www.merterelektronik.com/SILIKON-KALIN-BEYAZ,PR-41202.htmlYou can use that with a hot glue gun, it is silicon but white not transparent. You have black, red...Is this "silastic"?