k064as

I have recently repaired a section of my a/c and I used 30 minute epoxy on it. I now am not happy with how it looks and acts during flight. I have come up with a better fix for it and was wondering if there is such a thing as 30 minute debonder/remover. That would make the removal of the fix so much easier.

J_R

This might work

EdwardB

My Feedback: (6)

You likely won't be successful with any solvent based debonders. At least not without damaging something else. Generally epoxy can be softened with a heat gun. If it were me, I would mix up a test batch of the same epoxy, glue some scraps together, let them cure thoroughly, and then see if some amount of heat softens it up enough to take back apart. If so, and you can apply the same amount of heat to the model without damage, have at it!

k064as

Thanks for the info EdwardB, I'll give er a shot.


J_R, you're a moron.

FalconWings10

My Feedback: (4)

NO! there is no debonder. You'll do more harm than good.

BasinBum

My Feedback: (2)

JR may indeed be a moron but he's not the one that epoxied something the wrong way.

CafeenMan

MEK might break it down, but I've never tried it and the stuff is extremely hazardous. Not to mention it might make anything else that's close to what you're trying to take apart fall apart as well. Hope you can make sense of that last sentence.

the troll

I think that was JR's best post yet...the boy might have a since of humor...No hope for the Bum tho

Anyway... I have a chisel blade brazed to a soldering gun tip that is real handy taking things that are epoxied apart...especially stubborn broken hinges...Tell um where you got it from------------------------------------------------------





Those who trade liberty for security have neither.

Dan767

My Feedback: (19)

Take the covering off the area you want to repair. Get the heat gun out. Heat the area until the glue softens. Pull the glued area apart. Remove the glue from the affected parts with a putty knife or a razor. Works great.

Dan

I just need one more plane, honest!

Bule

Nice tool!!! J R where can I Get one of this?

J_R

kO64as

While I may be a moron, I am not the one using chemicals that I do not understand. For your future reference, all chemicals have material safety data sheets (msds). Do a Google search to find them.

While you can try many things, the MSDS will give you an indication of what is proper and what is not. I keep seeing posts that recommend heating epoxy for one reason or another. This is NOT good practice. It is one of the very few ways epoxy can get you in trouble.

My inital post was as a joke and factual at the same time. On chemicals like epoxy and RTV silocone, the recommended removal is mechanical.. not chemical.

Here is a portion of a MSDS, if you chose to heat it, do so at your own risk. Heating epoxy to make it less viscous causes the acceleration of the set up process and that is to be avoided as well. If you heat it enough, cured or uncured, you are asking for trouble from one of the few chemicals we use that is normally trouble free.

Hazardous products of decomposition:
Oxides of carbon; aldehydes, acids and other organic substances may be formed during combustion or elevated
temperature (>500 deg F) degradation.
Conditions under which hazardous polymerization may occur:
Heat is generated when resin is mixed with curing agents; Run-a-way cure reactions may char and decompose the
resin, generating unidentified fumes and vapors which may be toxic.
Incompatible materials:
Strong Lewis or mineral acids, strong oxidizing agents, strong mineral and organic bases (especially primary and
secondary aliphatic amines).
10. STABILITY AND REACTIVITY
This material is chemically stable.
Conditions to avoid :
Open flame and extreme heat
Hazardous polymerization will not occur.

JR

the troll

k064as
KAA..BOOOOMM...

Boy I knew that was coming...classic JR

well anyway here is proof of my point k064as

http://www.rcuniverse.com/forum/m_14...tm.htm#1410821

post #2

notice that the safety data sheets warnings are not present there...ROTFLMOPIMP

JR has a little book in which you and I are in now... My name is in red and underlined with 5 stars
-------------------------------------------------------------------------------------------

Those who trade liberty for security have neither.

J_R

Troll

In the case of aliphatic resin and acetone (titebond), there is simply nothing to warn about, other than the need for good ventilation.

When I post about chemicals that have problems, I do try to indicate warnings, such as cleaning engines with anti-freeze and the posionous nature of anti-freeze, if no one else has already posted it.

Heating epoxy with a heat gun can be a disaster, in the right set of circumstances. My heat gun is capable of in excess of 500 degrees at it's tip. The point of my previous post was to make available to those that are unaware, that information is at their fingertips about virtually every chemical we use. Not only for the original poster, but for all that read the post.

Let's keep our battle ground to the AMA forum. It's not sutiable elsewhere and is in violation of the rules of all the other forums.

JR

FLYBOY

My Feedback: (11)

All the bickering aside, the only way you will get it off is either the chissle and hammer as JR jokingly (but kinda funny) pointed out, or heat.

If you use a heat gun, do it carefully and where you have good ventilation. Don't get the heat gun close enough to burn the wood, but with enough heat, the epoxy will become flexible and you can get the part off, unless it is a balsa to balsa bond, and then you would probably just ruin both parts.

JRs point are valid though. Don't disregard them.

In building full scales, we use heat all the time to control the drying time of epoxy and also for changing the shape of cured parts. Do it carefully.

the troll

I guess since you say so get real... Typical J_R obfuscation...

He says as he loads another round...

JR I guess you didn't notice but my post was aimed at the thread starter and not you...somebody had to WARN him about YOU[X(] boy you thin skinned...



Anyway back to the topic...I almost forgot I first come to realize how well the technique works by heating a knife with a torch in desperation trying to remove a part from an airplane.... Of course when you deal with heat/fire/fumes/chemicals/tnt/speed/mother-in-law and Ford Explorers take care and use responsibly.

Anyway good luck and welcome to RCU...we are not all smart arses.

Combat Addict

I had luck removing a wing from a profile useing a dremel. Use a small carving attachment. Get to work. This isn't terribly fun. Also, I have found that a multi directional scroll saw cutting blade works well. Not a single edge one. Make handels out of ducktape and use it like a mini lumber jack saw.
Good luck.

k064as

Holy crap. I didn't at all mean to start a war.

To:

JR, when I called you a moron I was simply joking. I did find it very humorous (the tool, that is).
And JR, not only do I understand the chemicals I use, but I also have respect for them, that is why I am asking
you guys this before I go in full bore, or start doing any searches. I figured it would be quicker and more
interesting to here from fellow rc builders. Also I am fully aware what a MSDS is. Just had to throw that in.


BasinBum, if you would have read my original post you would have understood that I am not stupid enough to
glue something the wrong way, and that I am just unhappy with the fix. I understand that most fixes
will mess with tracking a little, little enough that sometimes you can't even tell. But this one was big enough that
not only could I tell, it just did not feel right. This whole subject is mostly about looks. And I thought you all
(probably being more experienced than I am, I've only been doing this a year) would have some good answers.
Which most of you did, and boy does JR know his MSDS. But your post hit me the hardest, you made it seem as if
I were a little boy playing with glue.

Volture

My Feedback: (1)

I have used a highly-focused heat gun to remove a bent wing joiner and tube from a wooden sailplane fuselage. Epoxy softens significantly with the application of heat, but you have to watch the surrounding wood.

CafeenMan

What's wrong with that?

BasinBum

My Feedback: (2)

ko64as,
We are all little boys playing with glue. How come JR shouldn't take your comment personally yet you took mine so personal? If you can't stand the heat stay out of the kitchen.

You asked a good question and got some good answers, don't take anything on the internet personal.

J_R

Sometimes, I really dislike the internet. It never allows for facial expressions, etc. I owe you an apology, and I mean that.

Next time, think about using aliphatic resin when you might want to change things later. If you use the interior stuff, you can use water as a debonder. If you use the exterior stuff, you will need to use acetone. It cleans up with water and makes it easier to do a nice installation of a stab or fin. It weighs a lot less when dry, as well. Don't try it on a bad fitting surface, like in a wing brace box. If it's a good fit, aliphatic resin is my adhesive of choice. Normally it sets up in an hour or two for handling, although you really want to let it set 24 hrs for max strength.

JR

CafeenMan

J_R - Are you saying I can use Acetone as a debonder for Titebond? Good to know. Thanks. [sm=thumbup.gif]

J_R

I use acetone, even on the interior stuff. I don't like how long water takes to evaproate and always worry about warping. But, yes, it works on titebond.

CafeenMan

Great! I'll update the adhesives page on my site. Thanks.

Covetski

is it really worth the time? just rip the glue off w/ an exacto knife and sand it