bonding dissimilar materials (HDPE to epoxy/fiberglass)

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#1

Hey yall

have a question for you gurus out there:
i need to bond, PERMANENTLY, epoxy / carbon fiber / fiberglass parts to HDPE parts. These bonded joints will be under high stress, subjected to powerful impacts regularly (constantly) and live in a saltwater environment when in use.

HDPE manufacturer says to quickly hit the HDPE part with a blowtorch just before bonding to cook/vaporize off the waxy outer residue, then bond the parts that need bonding, with whatever adhesive our research and trials lead us to. I know how to prep epoxy/glass/carbon parts for bonding, thats my life :amuse:

What magic goo should i use to do this? you guys got any recommendations?

heres what im up to lately, and what needs bonding in future production runs:
https://vimeo.com/157324184

find them here at our website:
www.thatwouldbebadass.com/boats

currently the boats are manufactured start to finish up by yours truly, we use a simple hand layup technique, with pretty good results so far.

thanks for any recommendations, and if you like em dont be afraid to check out our website.

-david

#2

I often use HDPE, nylon or delrin plastics specifically for releasing epoxy resins off so I imagine epoxies will not work here.

In my experience I can only suggest to look at Plexus Methacrylate, these have a mechanism of somehow really getting into other materials for good bonds.

Pg 28 http://www.itwplexus.com/UserFiles/File/Guide_To_Bonding.pdf

The guide above also lists many other adhesive types too.

#3

I’ve tested Plexus MA 590 and MA 300 for bonding HDPE to fiberglass and it holds but not well. Since you capped “PERMANENTLY” I’m going to assume that it is a critical requirement. I would not recommend either of those for HDPE and my rep didn’t have a better recommendation.

The only product I’ve found that works decently with HDPE is PE Fusion. It is expensive but it may do what you need. Here’s a link: http://graservices.com/products/peFusion/

#4

thanks guys! ill check those out.

another buddy of mine recommended a product called “G-Flex” by west systems. any thoughts?

thanks

-david

#5

ive also heard of using CA (superglue) on the HDPE first, its gives a key, never had the need to try it yet

#6

HDPE may be a difficult material to bond? If this fixing is so important then maybe you should consider actual fastenings or not using the HDPE??

#7

I did a project at work a few years ago where I had to bond ABS to HDPE and found that there were very few adhesives that will work with HDPE. I ended up using a Loctite product and was recently asked for more information. The one I used is no longer available but I came across this; Loctite 3035
It sounds like it might meet your requirements, and there is some good info in the brochure on the why HDPE is a challenge. Don’t expect it to be cheap, I believe I paid a couple of hundred dollars per tube and the dispenser is pricey too.

#8

G-Flex is epoxy.

CA glue does not work in a damp environment.

There are glues which bond PE, I believe 3M has a couple.

Searched for it, Scotchweld DP-8005 should do the trick.

#9

Herman, long time no see here!

Bonding HDPE is regularly done by oxidizing the surface. Burning it slightly. It is done in the G-flex epoxy video’s too, don’t know if they show it though. I suppose the PE glues would do something similar.

#10

HDPE is one of the most difficult plastics to bond to. I did a project at work that required this a few years ago and we used an expensive Loctite product. They now have something new out that sounds better; http://www.na.henkel-adhesives.com/adhesives/product-search-1554.htm?nodeid=8797965484033&msdsLanguage=EN_US&selectedTab=technical

#11

I can’t say I understand what parts are being bonded to what or how much impact they will be hit with but… I use epoxy putty for bonding when regular liquid resins aren’t enough. The epoxy putty I use will cure underwater and it is 't impacted by being wet after curing either. It stands up to the recoil of powerful firearms on the stocks I make.

I use it for bonding metal parts to carbon fiber. When done right, I can’t break them with my hands no matter how hard I try (and I have Incredible Hulk-like strength!)

If I need extra comfort that the bond won’t break, I wrap the the epoxy putty around the part so it isn’t just relying on surface to surface contact. It has around 5000 psi of flex strength. I am sure you can buy stronger putty if needed too.

I also use thixotropic urethane plastic for bonding sometimes. Urethane will stick an elephant to the ceiling and is quite possibly the stickiest stuff on earth. Have you tried high strength polymers?

#12

I have had to bond ABS to HDPE before and found that there are very few adhesives that actually claim to work and they are fairly expensive. The one I used was a Loctite product, can’t remember the actual one, but it appears to have been replaced by 3035, http://www.na.henkel-adhesives.com/industrial/product-search-1554.htm?nodeid=8797965484033
The earlier version that I used worked very well but was also over $100 for a 2 part tube and required a special dispenser that was expensive. There is some good info on there as to why HDPE is such a challenge.

#13

Loctite 3035 sounds like a suitable product, http://www.na.henkel-adhesives.com/adhesives/product-search-1554.htm?nodeid=8797965484033&msdsLanguage=EN_US&selectedTab=technical

#14

Look up Loctite 3035 Polyolefin bonder. I have used an earlier version of this with HDPE with good results. I responded about a month ago with a link, but it seems links prevent my posts from showing up.