On 1/8/2011 1:53 PM, Fuqua, Bill L wrote:
> In the past I have found problems with many adhesives that have solvents in
> them.
> The problem is whenever you have a gap to fill the adhesives shrink when the
> solvent evaporates. They fail later and if you look at the area where they
> were applied you will see voids between web like patterns . Only these thin
> webs connected the two surfaces. Superglue seems to turn brittle after a
> while and epoxy does not
Super glue is not a glue like most of us think of glues.
http://www.howstuffworks.com/question695.htm It does not fill voids and
is not meant to fill voids. Actually super glue works by forcing all the
air out and uses water molecules (really hydroxyl ions) to make the bond
by polymerizing. The surfaces need to be in intimate contact for it to
be the strongest.
> seem to work well in very thin applications. I have gone to RTV for many
> applications where two ridgid pieces need to be glued and some void between
> them
> needs to be filled. It does not shrink and gets better with time. The down
> side is that it does not adhear very well initally since it is fluid and
> needs time to
Two part epoxies are probably best for this. Ace Hardware has a number
of epoxies available in a two part dispenser that vary in working time,
cure time, and strength. Usually the longer cure time mixes give the
stronger bonds. Some are rated as high as 2 tons per square inch.
> cure. I have also used it with tube bases and plate caps on tubes. It takes
> high temp real well and since is does not become hard like epoxie does it
> does not stress the glass seals. GE products seem to be the best.
Nearly all of the major "RTVs" use the same formulations as it was never
patented. The original company decided they'd depend on staying with a
proprietary formulation and compounding. It worked for nearly 5 decades
before some one else figured it out. They contain Acetic acid and use
water vapor for the catalyst. They are water proof, but not water vapor
proof. Formulations are available from conductive to high voltage and
temperature tolerant. The High temp stuff is red. The electronic grades
contain alcohol instead of Acetic acid and "stink". They don't smell
like the typical alcohol but they won't dissolve the copper off your
printed circuit board either. BTW neither of these are the same as the
acrylic caulking compounds.
73
Roger (K8RI) Worked for one of the major producers of the stuff for years.
> 73
> Bill wa4lav
>
> ________________________________________
> From: amps-bounces@contesting.com [amps-bounces@contesting.com] On Behalf Of
> Commander John [crazytvjohn@yahoo.com]
> Sent: Saturday, January 08, 2011 1:28 PM
> To: Amps@contesting.com
> Subject: Re: [Amps] Adhesives
>
> I would use common spray glue used to stick artwork down. Craft stores etc.
> Any contact cement would work. I used spray glue to glue sand paper to
> sanders to do auto body work and still do at home.
> It will come off when heated so it would not work so well on anything hot.
> It is very similar to what is on self stick stickers etc.
> john W9ZY
>
> --- On Sat, 1/8/11, Mike Krzystyniak<k9mk@flash.net> wrote:
>
>> From: Mike Krzystyniak<k9mk@flash.net>
>> Subject: [Amps] Adhesives
>> To: amps@contesting.com
>> Date: Saturday, January 8, 2011, 7:49 AM
>> I have a DTR-2000
>> amp from Dentron. The metalized label on
>> the back has lifted about half way off starting from one of
>> the corners. It seems like the lifted part of the
>> label to have lost its stickeynesss. I want to
>> reattach the label but due to the springy quality of the
>> material I question which type of adhesive to apply.
>> Any suggestions?
>>
>> Thanks in advance.
>>
>> 73's Mike K9MK
>>
>>
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