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        3M 77 alternatives for styrofoam

#1 Armchair Bronco Oct 17, 2004 02:35 AM

3M 77 alternatives for styrofoam
 
Too bad 3M started adding acetone to Super 77 a year or two ago. :mad: The new stuff doesn't eat EPP, but it'll melt styrofoam.

What should I use to make styrofoam wings tacky for applying packing tape (clear & fiberglass re-inforced)?

Are there any alternatives to 3M Super 77 (other than the obvious answer of tracking an old bottle of the black stuff)?

#2 Synth Oct 17, 2004 03:41 AM

Try Elmers. I hear it's much milder and is ok for styro.You should be able to find it at your local hardware store.

#3 Armchair Bronco Oct 17, 2004 06:09 AM

There must be some spray on alternative to elmers.

With an old can of '77, I could have sprayed my entire plane in 10 15 seconds. Plus, I don't think I'd get comparable tackiness with elmers: wouldn't it go on wet and mess up the packing tape?

#4 Pinecone Oct 17, 2004 07:21 AM

3M 90 will work. I have heard you can get it at Home Depot, but I haven't checked.

You can also order it from Hillas packaging (www.hillas.com). The trick is, when you click add to cart, it adds an entire case, just change teh number to the number of cans you want. They stock it and will sell it by the single can. SOme stuff in their online catalog is case lots only.

Another neat thing they carry is 9mm wide filament tape. No more spliting 3/4" down to 3/8", 9mm is just under 3/8".

#5 M Ashmore Oct 17, 2004 07:44 AM

3M 77 works just fine. All you have to do is hold the can away from the foam about 10 to 12 inches to let the propellent evaporate. You get a much wider spray pattern, of course, so masking is a must. I've used it on all kinds of foam with no issues at all.

#6 Waldo Pepper Oct 17, 2004 07:53 AM

Rumor has it that 3M 78 is the "old" 77 spray. This from foamfly.com

wp

#7 omega blood Oct 17, 2004 08:55 AM

Quote:

Originally Posted by phat23
3M 77 works just fine. All you have to do is hold the can away from the foam about 10 to 12 inches to let the propellent evaporate. You get a much wider spray pattern, of course, so masking is a must. I've used it on all kinds of foam with no issues at all.

This is true.
This wing is all eps wing and I used the new 3-M77 to spray before covering with out a problem. http://www.rcgroups.com/forums/showp...81&postcount=2

#8 rcmann Oct 17, 2004 09:51 AM

You can also pull out a length of tape, spray the tape (rather than the EPS), let it dry for 10-15 seconds and apply it to the EPS. I used this method recently and the tape stuck really well.

#9 windtrader Oct 17, 2004 02:44 PM

1 Attachment(s)
Quote:

Rumor has it that 3M 78 is the "old" 77 spray. This from foamfly.com
Probably fact. Attached is the application guide for the 3M spray adhesives. Nice reference to have around.

#10 rcmann Oct 17, 2004 03:00 PM

3M78 looks like the ticket, but where do you buy it?

#11 Old Man Oct 17, 2004 04:43 PM

I emailed 3M about to old 77 and they told me that they are still making it. The new formula is due to a California environmental law. They gave me a list of suppliers to contact. I contacted Graingers about getting the old fomula. I ordered a case of the old 3M 77 at $6.00 per 16.5 oz can! They list both the new and the old formula in their catolog. The formula you want is 3M id. #62-4437-4930-4.

#12 Armchair Bronco Oct 18, 2004 10:41 AM

Woo hoo! Thanks for the tips and contact numbers. Figures it would be a California law that got in the way of easy access to "Old School" 3M 77...

#13 FRAMEDNLVS Oct 19, 2004 04:16 PM

gone fishing

#14 Ronbo Oct 20, 2004 01:58 AM

use 3m 61, corner bead. is about 5-6$ a can, same size as 3m 77 same stuff, just comes out pink so you can see it.

#15 windtrader Oct 20, 2004 11:21 AM

@old man -

Quote:

I contacted Graingers about getting the old fomula. I ordered a case of the old 3M 77 at $6.00 per 16.5 oz can! They list both the new and the old formula in their catolog. The formula you want is 3M id. #62-4437-4930-4.
I just looked at the online Grainger catalog and in their hardcopy catalog #395. Neither shows the original formula. The online 3M catalog shows the stuff you bought but is listed as obsolete (in the 16 oz packaging). They do show it current as the "original" in 24oz cans which does not show in the Grainger catalogs.

You must have gotten lucky and found some of the old stock still in inventory somewhere.

http://products3.3m.com/catalog/Http..._1098289076676


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