FlybyPDX

My Feedback: (2)

Every time I use this it is sticky forever..... until it gets so dirty that I want to throw it away.


Is there anyway I can avoid this?

I am using it right now on a speedwing. It sais in the directions to put a light cover over the whole thing.

buttuh

The formulation for the 3M Super 77 changed last year due to EPA regulations in California. I stopped using it because it's much different from what it used to be, besides the fact that it sticks. Supposedly Airtech has a tack spray that doesn't do this but I haven't tried it yet. So for now I'm just using up the old stocks of the Super 77 wherever I can find them.

FlybyPDX

My Feedback: (2)

I must have the old one then. Its like 2 yrs old

ERichard

The original formula is still available...unless you live in CA.
Check out the following link:

http://products3.3m.com/catalog/us/e...er/output_html

-E

NAES

I just wipe it off with laquer thinner, brake cleaner or paint thinner. No problem at all unless your covering is going to suffer from the solvents.

TT2

My Feedback: (13)

buttah and everyone else, why don't you like the newer formulation of 3M77? What is so different about it that is preventing you from using it?

I have used the new formulation for laminating sheets of 2" Styrofoam together for plug making and haven't had any problems there. I have found that it doesn't attack foam to the degree the naysayers said it would. My feelings are that if it's eating the foam you are spraying it on WAY TOO THICK. Just shoot a mist coat on both surfaces, wait a few minutes (during which time most of the acetone carrier will flash off), then laminate and bag. No sweat! The joint seems just as strong as the old 3M77...strong enough to chunk the foam when it's pulled apart.

I have also used it for tacking dry substrates in place when using VARTM. Carbon, glass, whatever. No problems there either. Could it possibly be creating problems that I cannot see? The parts seem just as strong as when NO tacking adhesive is used. Maybe it's incompatible with vinyl ester resins? I only use epoxy (for now), so I have no comparison point in that regard. Once again, I use as little 3M77 as possible when laying in the cloth...usually just a misted stripe to keep the substrate from shifting in the mold.

I have used over 20 cans of the new formulation and can honestly say that it's use hasn't impacted my operations one bit. I thought about trying the new AirTech tack spray among others available, but can't really see why I should even bother.

What am I missing? Help me solve the mystery.

-Tom

phil barnes

I agree with Tom. The following is a reprint of a post to another group;

It turns out that the best substitute for old ("classic)3M77 is the new
(acetone based) 3M77. The whole 3M77 scare was largely a false alarm. I used
a couple cans of the new acetone based stuff and found that it really didn't
melt foam on any of the operations that I normally use it for. The only way
it melts foam is if you spray it very heavily, directly on foam and maybe
even let a wet puddle of it sit there. The acetone mostly evaporates before
it has a chance to melt foam.

I still prefer the classic 3M77 because it dries more slowly and I am more
accustomed to it. I still have about 30 cans of the classic stuff left. When
that runs out I will attempt to buy more of it. Others have posted that it
is still sold but it is not generally distributed to retail stores anymore
and you need to order it from 3M distributors, perhaps in full cases.

From another old post, this is one place that will sell and ship the classic formulation;

The old formula 3m 77 can be purchased by the case (12) in Pennsylvania
at Xode Inc. They have it in stock, and will ship it.
www.xode.com
Ph. 610-683-5363
Ask for Tod Elliot

This is a response from a 3M representative about catalog numbers for the two versions of 3M77;

3M Super 77 has had a few formulation changes.
These changes were in order to meet government
VOC standards. We currently sell two versions of
3M Super 77 - the original "classic" version stock
number is 62-4437-4930-4 and the current formulation
for 3M Super 77 Low VOC is 62-4977-4930-9

Here is a link to the 3M web site showing the two versions;

http://products3.3m.com/catalog/us/e...er/output_html

Wow! That's a long URL. Assuming it works, scroll down a bit to see the two versions of 3M77 listed.

TT2

My Feedback: (13)

Congrats on the IHLGF win Phil! I haven't flown HLG for six years (I think my last HLG was a Monarch fuse with one of my own wings) but the article in MA certainly sparked my interest in HLG / DLG once again. After I get some projects off the tables I'm going to start working on a fuselage plug.

-Tom

TGDF

My Feedback: (3)

You might try a can of 3M 75 Repositionable Adhesive. I may have used the 77 a long time ago. Whatever it was, I thought it was way to sticky for gentle work which is going to be epoxyed in place anyway.

75 is tacky enough to stick to wax paper but it is EASILY taken up and replaced. And as you can temporarily stick the workpiece to waxpaper anyway, you can easily keep it clean.

Forget about Krylon Repositionable. It only costs 1/3 or less than 3M but it must not be clean in the can. It spits out drops which leave rusty black stains on e glass and even when you soak the glass it barely sticks to itself let alone anything else. The 3M is clear. Just remember to bring along some breathing air if you use either one inside.

FireScout

I found a different product that works as good as the original formula 3M77 and costs half as much. It does have acetone, but doesn't appear to attack foam when sprayed at 12". CRC Industrial Spray Adhesive, available at Harbor Freight.

Tom