# Research 2070 Laminating Epoxy

### Help Support The Rocketry Forum:

#### NateLowrie

Unless you can save shipping or something, the US Composites 635 laminating resin at $71 for a "gallon" kit is a bit cheaper and the kit also has a full gallon of resin and a 1/3 of a gallon of hardener. Its easy to work with and is fairly tolerant of temperature. Second the suggestion of US Composites 635 resin. Use the 3:1 hardener. It wets out really nice. #### Handeman ##### Well-Known Member TRF Supporter The US Composites is what I started with and it's the only one I've ever used. I never found a reason to change. #### REK ##### Sponsor TRF Sponsor Anyone tried this epoxy? It's formulated to penetrate and completely wet out fabric. It's also really affordable at$79 for a gallon.

If it penetrates well enough, I'm also thinking of using it to reinforce some 8" mailing tubes followed by a wrap or two of some epoxied drain sleeve. Would be heavy but tough.
Every resin has its pros and cons. It all depends on how your going to do your project. I have not tried this resin to compare to others that I have used.

In my honest opinion, low viscosity resins are always best to use.

Sent from my iPhone using Tapatalk

#### mccordmw

##### Well-Known Member
Ok. I have ordered some US Composites 635 with the medium time hardener. I'm using it to apply a Drain Sleeve sock on to a series of peeled, 8" sonotubes. Hopefully, it does the job.

#### BDB

##### Absent Minded Professor
Ok. I have ordered some US Composites 635 with the medium time hardener. I'm using it to apply a Drain Sleeve sock on to a series of peeled, 8" sonotubes. Hopefully, it does the job.
Please tell us how the drain sleeve sock works. I haven't had the time to look into comparing it to the easy glass sock yet, but I'd love to see how it works for you.

#### mccordmw

##### Well-Known Member
Please tell us how the drain sleeve sock works. I haven't had the time to look into comparing it to the easy glass sock yet, but I'd love to see how it works for you.
Sure thing. I'll start a thread on drain sleeve (polyester knit tube) epoxy lamination on cardboard tubes.

#### REK

Just curious, but why not just use a fiberglass sleeve?

Sent from my iPhone using Tapatalk

#### mccordmw

##### Well-Known Member
Just curious, but why not just use a fiberglass sleeve?

Sent from my iPhone using Tapatalk
Price! An 8" x 100' long polyester sleeve is about $25. A 4" fiberglass tube runs about$3 per foot. Also, the polyester tube is thought to be plenty strong enough for most general HPR. It's supposedly similar to stuff sold by Giant Leap as glas sock, but much cheaper as well.

#### REK

Price! An 8" x 100' long polyester sleeve is about $25. A 4" fiberglass tube runs about$3 per foot. Also, the polyester tube is thought to be plenty strong enough for most general HPR. It's supposedly similar to stuff sold by Giant Leap as glas sock, but much cheaper as well.
Yeah I understand about price. Now about strength, most epoxies are rated from 8,000 to 10,000 psi without any fiber reinforcement. Obviously polyester is not as strong, but it should give some additional strength.

For use in general HPR it should suffice.

Sent from my iPhone using Tapatalk

#### mccordmw

##### Well-Known Member
Yeah. I've even considered just painting the laminating epoxy on to the tube and letting that soak in to see if that adds sufficient strength on its own. If that was good enough, I'd think that would be a more common practice.

Since everyone seems to do a layup of FG or other fabric, I'd assume there's a reason. The fabric, while not adding much strength itself, might add much more strength when applied with epoxy? Not sure. I'd defer to the experts here if they know why. I'm a neophyte when it comes to fiberglassing tubes.

#### REK

Yeah. I've even considered just painting the laminating epoxy on to the tube and letting that soak in to see if that adds sufficient strength on its own. If that was good enough, I'd think that would be a more common practice.

Since everyone seems to do a layup of FG or other fabric, I'd assume there's a reason. The fabric, while not adding much strength itself, might add much more strength when applied with epoxy? Not sure. I'd defer to the experts here if they know why. I'm a neophyte when it comes to fiberglassing tubes.
The strength with glass and carbon always depends on the number of layers and the weight of the fabric. Adding just one layer of 4oz glass is not enough. It will take at least 3 or 4 layers of 4oz glass to get good strength out of it.

Im pretty sure you can just paint the epoxy on, but I think it runs and drips more easily. I believe that is the purpose of the sock, to make applying epoxy less messy.

Despite not being glass or carbon, the polyester should still add just a small amount of strength.

#### mccordmw

##### Well-Known Member
I was planning on just one layer to hold all that epoxy in. Those sonotubes are pretty think and would absorb a lot of the epoxy. Might get super heavy, but it should be pretty strong. I'm not sure how much more strength a wrap of this sleeve will add. The main benefit might be just giving a smoother surface? I'm wrapping it with mylar and vac-bagging to make it smooth plus help absorb all the epoxy into the tube. We'll see. I'll try to include lots of pics.

Probably going to start with a really short section to learn the mechanics of doing it without wasting lots of materials.

#### REK

I was planning on just one layer to hold all that epoxy in. Those sonotubes are pretty think and would absorb a lot of the epoxy. Might get super heavy, but it should be pretty strong. I'm not sure how much more strength a wrap of this sleeve will add. The main benefit might be just giving a smoother surface? I'm wrapping it with mylar and vac-bagging to make it smooth plus help absorb all the epoxy into the tube. We'll see. I'll try to include lots of pics.

Probably going to start with a really short section to learn the mechanics of doing it without wasting lots of materials.
Im sure it will give it some structural strength. Not as strong as glass or carbon, but will do the job.

Will be watching, I have done plenty of tubes (including sleeves) with glass, kevlar, and carbon, so I will do my best of my knowledge to assist on this.

Sent from my iPhone using Tapatalk

#### Nick@JET

##### Well-Known Member
Im sure it will give it some structural strength. Not as strong as glass or carbon, but will do the job.

Will be watching, I have done plenty of tubes (including sleeves) with glass, kevlar, and carbon, so I will do my best of my knowledge to assist on this.

Sent from my iPhone using Tapatalk
You should consider a tutorial thread Alexander, you've got a lot of experience and I would like to learn lay ups as well!

#### mccordmw

##### Well-Known Member
Since Sonotube is so cheap, I'm thinking do a quick comparison of 1' sections:

- untreated sonotube
- epoxy painted tube wo/sleeve
- sleeved and painted
- epoxy painted tube then sleeved and painted again

Check weights.
Put them on a scale and see how much crush force they can take.

Curious as to the difference.

#### markkoelsch

##### Well-Known Member
Just painting with epoxy is going to just add weight- pretty well known.

The strength from a composite is due to the fibers of reinforcement material being held in a matrix of epoxy.

#### BDB

##### Absent Minded Professor
I love the idea! I'm still planning to do something similar to compare 4" LOC tubing with a easy glass sock and a kevlar sock. You're going to have to build a little bigger contraption than I did to handle the sonotube.

#### mccordmw

##### Well-Known Member
I ordred a few large, wood circles from here:

https://woodcrafter.com/plywood-circles/

Hard to bear $2.64 for an 8" x 1/8" baltic birch plywood circle. Going to drill holes in them and slide a broomstick through. I'll use those as a mandrel to holld the sonotube on my sawhorses. The sawhorses have indents in them to hold a rod. Should work out well. #### REK ##### Sponsor TRF Sponsor You should consider a tutorial thread Alexander, you've got a lot of experience and I would like to learn lay ups as well! I will do so when I get the chance. I started a thread awhile back, but making videos was a little difficult and so a simple write up with pictures would be best. I also need to do like a pre-write up so I can keep it simple. Sent from my iPhone using Tapatalk #### mccordmw ##### Well-Known Member This weekend I did a little experiment. I cut off two 1' sections of 8" diameter Quikrete tube to test with a drain sock lamination and a control. I've read about needing to sand off the outer paper since it prevents good epoxy adhesion. However, the downside is that the exposed cardboard soaks up crazy amounts of epoxy. So I tried this. The Quikrete tubes were sprayed with 2 coats of adhesion promoter-primer. It's a clear primer designed to make the surface readily available for binding. Once the volatile organics dry off, there is almost no added weight. This stuff will allow you to paint PVC with no problems. So I gave it a test with the epoxy. Last night, I mixed up some US Composites epoxy with the 3:1 medium hardener and put on two layers of drain sleeve. I didn't bother putting on mylar to make it pretty since this is just a test. This morning, I checked the results. The laminate looked good; not too wet and not too dry. The tube hardly soaked up any extra epoxy. The 1' length only gained about 50g of expoy weight (when I subtracted the drain sleeve weight). So I assume most of the epoxy is in the cover with minimal soaking into the tube. I tried peeling off the epoxied drain sleeve with pliers, and I couldn't do it without taking along half the tube with it. I put a 2x2x1/2" piece of plywood on top and jumped on it. No crushing or buckling. The dry tube also held up to that, so all I can really say there is that the epoxy or primer didn't soak into the paper tube and somehow weaken it. Laterally, the tube does seem much stronger. Tonight, I'll test lateral crush. I'll see how much weight it takes before it crushes. Has anyone else tried this? It seems to hold the laminate well while giving some extra strength without too much added weight. Now I wonder how well a real fiberglass wrap would do. Thoughts? Last edited: #### mccordmw ##### Well-Known Member #### REK ##### Sponsor TRF Sponsor This weekend I did a little experiment. I cut off two 1' sections of 8" diameter Quikrete tube to test with a drain sock lamination and a control. I've read about needing to sand off the outer paper since it prevents good epoxy adhesion. However, the downside is that the exposed cardboard soaks up crazy amounts of epoxy. So I tried this. The Quikrete tubes were sprayed with 2 coats of adhesion promoter-primer. It's a clear primer designed to make the surface readily available for binding. Once the volatile organics dry off, there is almost no added weight. This stuff will allow you to paint PVC with no problems. So I gave it a test with the epoxy. Last night, I mixed up some US Composites epoxy with the 3:1 medium hardener and put on two layers of drain sleeve. I didn't bother putting on mylar to make it pretty since this is just a test. This morning, I checked the results. The laminate looked good; not too wet and not too dry. The tube hardly soaked up any extra epoxy. The 1' length only gained about 50g of expoy weight (when I subtracted the drain sleeve weight). So I assume most of the epoxy is in the cover with minimal soaking into the tube. I tried peeling off the epoxied drain sleeve with pliers, and I couldn't do it without taking along half the tube with it. I put a 2x2x1/2" piece of plywood on top and jumped on it. No crushing or buckling. The dry tube also held up to that, so all I can really say there is that the epoxy or primer didn't soak into the paper tube and somehow weaken it. Laterally, the tube does seem much stronger. Tonight, I'll test lateral crush. I'll see how much weight it takes before it crushes. Has anyone else tried this? It seems to hold the laminate well while giving some extra strength without too much added weight. Now I wonder how well a real fiberglass wrap would do. Thoughts? You want to let the epoxy soak in, despite many will say its dead weight, it really isnt. This is mearly to add enough strength to make it robust. You can take a phenolic tube and soak it with thin CA and it gets really strong. Much like wood as well if soaked with epoxy it gets stronger, due to the resin soaking through it. Is the weight factor really an issue? I would consider making another test piece with soaked epoxy and the sleeve. This way you can compare all three and go with what you are most comfortable with. Sent from my iPhone using Tapatalk #### shahsazib ##### New Member I ordred a few large, wood circles from here: https://woodcrafter.com/plywood-circles/ Hard to bear$2.64 for an 8" x 1/8" baltic birch plywood circle.

Going to drill holes in them and slide a broomstick through. I'll use those as a mandrel to holld the sonotube on my sawhorses. The sawhorses have indents in them to hold a rod. Should work out well.
Hi, I found another wood circles: https://www.build-a-cross.com/circle-unfinished-cutout-wooden-shape-paintable-wooden-mdf-diy-craft/