No More Peeling Tubes for Me

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mccordmw

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I've been working on my L3 project that involves fiberglassing lengths of 8" Quik-tube/Sonotube. These tubes have yellow, waxy paper on the outside that interfere with good bonding of the epoxy/fiberglass. That will cause delamination problems and a compromise to the strength. To fix this, most people either sand off the paper or peel it off. This fixes the sticking problem, but it comes at a cost. The porous, fuzzy paper will now absorb epoxy like a sponge. All that extra epoxy does not do much at all for strength, but it does increase the weight of the tube tremendously. Plus, epoxy isn't cheap, and it's wasting money.

I've been looking at alternative ways to get over this problem. After a few experiments with chemical treatments, I think I've found the perfect solution; adhesion promoter. I'm now using Dupli-color Adhesion Promoter spray.

https://www.amazon.com/dp/B0007UAXJQ/?tag=skimlinks_replacement-20

From what I could find out, it seems the Dupli-color adhesion promoter is a chlorinated polyolefin in a mix of organic solvents which break up waxes/plastics/oils while the polyolefin provides a surface for molecular bonding between the paper and the epoxy while adding no noticeable weight (as was seen when measuring). Normally, polyolefins definitely do not allow epoxy to stick. However, the chlorination fixes this problem.

I applied two very wet coats of adhesion promoter to a 12" section of scrap Quik-tube (inner wax layer was peeled), and left it to dry. As a control, I peeled off the outer paper on another 12" scrap tube and left this untreated. After spraying the test piece and allowing to dry for an hour, no difference can be seen, but the surface has a slightly chalky feeling (might be in my imagination, though). The primer is mostly volatile solvent, so it did not add any weight to the scrap once dry.

Both scraps were epoxied with scraps of 6 oz. fiberglass for two wraps using US Composites 3:1 resin. End weights were compared.

Test Set:
Bare tube (inner wax lining peeled off): 19 g/in
Primed with adhesion promoter: 19 g/in
2 x layers 6 oz. fiberglass: 35 g/in

Control Set:
Bare tube (inner wax lining peeled off + outer paper peeled off): 13 g/in
Priming skipped...
2 x layers 6 oz. fiberglass: 41 g/in

The sprayed tube is significantly lighter per inch. The next tests were qualitative only.

Bubbles or delaminations:
Test: none seen
Control: none seen

Peel test:
Test: unable to peel off fiberglass without complete destruction of tube
Control: unable to peel off fiberglass without complete destruction of tube


Lateral compression was also crudely tested. Both took approximately the same amount of force to crush by squeezing. This is as expected.

I also scaled up and laminated a complete 48" tube, unpeeled, primed, and wrapped with 2 layers of 6 oz fiberglass. The weight came out very similar. There will be differences depending on how well excess epoxy is squeegeed out. The end result was the same; no bubbles or delaminations, and a much lighter tube than anticipated if the outer wrap was peeled off.

20170116_215026.jpg

I tested a scrap 38 mm LOC MMT tube with glassine last night. Primed and wrapped. As of this morning, it looked like it stuck perfectly fine with no delamination. I'll inspect it more closely tonight since it's a bit tough to spot a potential bubble on a white tube. I'm hopeful.

Has anyone else tried adhesion promoter? I'm sold from now on every time I wrap.

I'd love for more experienced fiberglassers out there to test this and give feedback.
 
Last edited by a moderator:
I have used Duplicolor Adhesion Promoter for 10+ years, but only for paint/primer applications.
 
Thanks for the thread and do you sand the plastic nose cone at all before applying the adhesion promoter?

Thanks,
StanO

I sand down the seams to get them flat, but not the whole nose cone. The adhesion promoter was specifically designed to allow painting of plastics and metals, so it works really well. On one nose cone for a scratch build, the wimpy LOC plastic loop broke and the cone fell from 2000' to bounce. None of the paint flaked off from the impact. I've had paint flake off before when sanding and priming without using adhesion promoter. That's the reason why I looked into this stuff; to get better plastic painting results.
 
Thanks for the thread and do you sand the plastic nose cone at all before applying the adhesion promoter?

Thanks,
StanO

Good video to show how well adhesion promoter does to make polypropylene plastic accept adhesives.

[video=youtube;dBRIyhmYMuI]https://www.youtube.com/watch?v=dBRIyhmYMuI[/video]

And a good display of how well the adhesive promoter gets paint to stick to plastic.

[video=youtube;m7-T1VhPZng]https://www.youtube.com/watch?v=m7-T1VhPZng[/video]
 
think this would be good for what I want to do 6 -10 inch sono
 
but my plan it was going to be very heavy . still looking at my options for mine
 
Can this product be used with paints like Rustoleum 2X, or would one have to stick with Duplicolor products after using it?
 
I sand down the seams to get them flat, but not the whole nose cone. The adhesion promoter was specifically designed to allow painting of plastics and metals, so it works really well. On one nose cone for a scratch build, the wimpy LOC plastic loop broke and the cone fell from 2000' to bounce. None of the paint flaked off from the impact. I've had paint flake off before when sanding and priming without using adhesion promoter. That's the reason why I looked into this stuff; to get better plastic painting results.

Thanks for your response. I subscribed to this thread but did not receive email notifications or I would have responded sooner. Another digital mystery. I will be using the product.
StanO
 
I just followed this procedure to glass a 3" Estes tube for a modified Scion. I'm hoping to use it as a test vehicle for some sugar motors that I'm building, so I wanted to add a little durability while keeping it light.

The adhesion promoter was a piece of cake to apply. After dying overnight I laid up one wrap (24 g) of 2 oz glass, and I didn't even need to use 24 g of epoxy to completely wet it out.

ImageUploadedByRocketry Forum1486924657.896493.jpg

(I can't believe my let my wife do this in our kitchen. You can barely see it in the window, but there's a blizzard outside right now.)
 
I just followed this procedure to glass a 3" Estes tube for a modified Scion. I'm hoping to use it as a test vehicle for some sugar motors that I'm building, so I wanted to add a little durability while keeping it light.

The adhesion promoter was a piece of cake to apply. After dying overnight I laid up one wrap (24 g) of 2 oz glass, and I didn't even need to use 24 g of epoxy to completely wet it out.

View attachment 311634

(I can't believe my let my wife do this in our kitchen. You can barely see it in the window, but there's a blizzard outside right now.)

Cool! The wrap looks great. Zooming in, I couldn't see any bubbles or other indications of poor adhesion to the tube. I hope the results are what you want. I didn't see a need to let the tube dry overnight. The volatile organic solvents in the spray dry super fast. I just let it dry 30' to 2 hours for my wraps. Just an FYI if you're wanting to do layups earlier.

Good luck. I'm building a stock Scion with my 9yo right now for Spring launches. He can't wait to paint it. My 13yo is jealous that it's bigger that his Solar Express. :p
 
The majority of the imperfections are from bristles falling out if my chip brush. Even the ends and the seam look pretty good. Granted, this is only one wrap of 2 oz glass, but I'm really happy with the result.
ImageUploadedByRocketry Forum1486999772.286743.jpg
ImageUploadedByRocketry Forum1486999786.795002.jpg
 
A bonding topic search brought me back here lol.

Anyone know if Loc nosecones are PP (polypropylene) based? I've got some adhering to do!
 
A bonding topic search brought me back here lol.

Anyone know if Loc nosecones are PP (polypropylene) based? I've got some adhering to do!

Yes, thanks for digging up this thread. I'd never heard of this adhesion promoter before. I was just about to paint a bunch of nose cones, after using monokote vinyl wrap on the body tubes...
 
A bonding topic search brought me back here lol.

Anyone know if Loc nosecones are PP (polypropylene) based? I've got some adhering to do!

And to specifically answer your question...Yes, the LOC nose cones are polyproylene based...see their website description, or the screen shot I'm attaching (if attaching works...)Screen Shot 2018-01-17 at 3.49.08 PM.png
 
Yes. I sprayed a LOC 3.0 nosecone with this before priming and painting. Worked like charm. All I did was sand down the seam.

I'll be epoxying as well as painting, so good to know.

Thanks again for your documentation threads Mark, they're great!
 
The concrete tubes i found at lowes have a good amount of the wax on the inside, should it be scraped off before using adhesion promoter? These tubes are funny they all say 8" nominal so some fit inside each other.
 
The concrete tubes i found at lowes have a good amount of the wax on the inside, should it be scraped off before using adhesion promoter? These tubes are funny they all say 8" nominal so some fit inside each other.

Those tubes are not kept to a standard. Finding a good set that will act as body and coupler is pretty rare from what I've heard.
 
Yeah i stood there 20 minutes measuring them out with a new tape measure, i've looked at them before for a project i started awhile ago only because the original tubes (i got from work) were damaged. Caught my eye today when i was walking down the isle because some were almost flat then i noticed tubes were set inside each other. For $8 i picked one up and it fits the motor mount good, thats with that wax in it though.
 
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