A little help with Soller glassing?

[Kelly]

I used a Soller glass sleeve for the first time the other day, and had a couple issues maybe you guys could help with.

I followed the videos/info I've seen: put a couple CRs in the tube and inserted a dowel, put the sleeve on, fastened the ends. I mixed up epoxy (about the same weight as the sleeve), applied with a brush, and then used a credit card to squeegee all the excess resin out after the glass and tube were thoroughly wetted. Put a heatshrink sleeve on, and use the heat gun.

My issues:
1) I was led to believe there would not be any longitudinal shrinkage in the heatshrink (<1%), but I actually got >10%, so the wrap shrunk up more than I allowed for, and I was left with an inch or two on each end that didn't get wrapped. Is this typical (the shrinkage)? Do you guys normally do something to fasten down the ends of the heatshrink?

2) After removing the heatshrink, the glass weave texture is still visible on the surface. Did I squeegee too much epoxy off? How do I know how much epoxy to leave in, to get a glass-smooth finish after the heatshrink, but not too much excess weight?

Thanks,

Kelly

 

[John Kemker]

1) No answer for you.

2) No, you did not squeegee too much epoxy off. What you're looking for is the minimum amount of resin necessary to "wet out" the glass and no bubbles. Sounds like you did that, so you're good. If you want a perfectly smooth surface, I'd recommend using a body filler putty or CWF to fill in the weave, then sand and paint. You might even be able to get that perfectly smooth surface with a high-fill primer.

I just vacuum bagged a plywood fin for my USR Swarm clone. It still has the weave texture. Not a problem. I'm on my second fin and expect the same results. Since I still need to epoxy them onto the fiberglass rocket, I don't mind a bit of texture to "grab" the epoxy. Saves me from having to sand them prior to application. I'm still going to have to do that to the tubes, but one less thing to sand is not a bad thing.

 

[Kelly]

Thanks John! Yeah, I always thought the goal was to get as much resin out as possible. But I thought the whole purpose of the heatshrink was to get a glass-smooth finish. Maybe that's just not possible with the 6oz weave that I used. It's definitely far better than the parts of the tube that got no shrink. And yes, my filler/primer might be able to do the the trick.

 

[G_T]

Take a scrap of the heat shrink, shrink it, and measure the shrinkage.

Odds are your tube absorbed some epoxy, pulling the surface down. There is also shrinkage when epoxy cures. It is not much, and occurs mostly near the end of the cure. So it pulls in slightly towards the tube anywhere it can.

You avoid print-through by a few different methods, but heat shrink isn't going to be one of them. A rigid tooling surface combined with moderate pressure (say, 40psi) can get you close. AKA a mold. But it still won't be perfect due to that slight late epoxy shrinkage.

Using an outer surface fabric with more completely filled finer weave helps a lot. Spread tow fabrics help as well, being sort of an ultimate in that regard.

When glassing the outside of a tube, the tooling layer is unfortunately the the tube which is not the outer surface.

I'm not sure anybody has tried it, but if the tube is reasonably tough I'd be tempted to find a clown balloon that inflated is just a hair bigger than the ID of the tube. Put the sleeve on that, slide it in the tube, and then inflate. Keep it inflated until cured. Deflate, and twist up an end to peel it out. That is, put the glass on the inside. A pump helps with inflation. You don't want to be mouthing an epoxy coated balloon. That can go bad in so many different ways!

Gerald

 

[tg08]

For question #1, yes I do secure it. I use dura-lar instead of heatshrink, but I use zip ties to secure the ends of the dura-lar.

 

[Kelly]

Thanks Gerald, that's useful info.

BTW, I have tried the inside glassing (with a balloon) trick, but not with a full body tube. I've used this trick to create couplers (using the glassing to seal the crack between the cut ends) and also to reinforce the inside of a 3D printed nosecone. Works well.

 

[KenECoyote]

1) I was led to believe there would not be any longitudinal shrinkage in the heatshrink (<1%), but I actually got >10%, so the wrap shrunk up more than I allowed for, and I was left with an inch or two on each end that didn't get wrapped. Is this typical (the shrinkage)? Do you guys normally do something to fasten down the ends of the heatshrink?

How long was your tube?

According to the Soller site:

"The tubing shrinks very little lengthwise. Allow 1inch for every 10ft."

 

[Kelly]

M

How long was your tube?

According to the Soller site:

"The tubing shrinks very little lengthwise. Allow 1inch for every 10ft."

My tube was 37". I left a half inch overhang on each side. I ended up with about an inch and a half exposed on each end.
So, one inch in 10 feet is less than 1%; the 3-4" of shrink I got is over 10%.

 

[OZRoc]

I've only done this once so I'm in the same boat.
1. Yes, overshrunk on one end.
2. I didn't squeegee the resin out and got a nice smooth finish under the heatshrink albeit with a few pockmarks (ie bubbles) that will be easily filled. The end that missed the shrink I'll just bog up.
Cheers,
Mark

 

[jahall4]

I used a Soller glass sleeve for the first time the other day, and had a couple issues maybe you guys could help with.

I followed the videos/info I've seen: put a couple CRs in the tube and inserted a dowel, put the sleeve on, fastened the ends. I mixed up epoxy (about the same weight as the sleeve), applied with a brush, and then used a credit card to squeegee all the excess resin out after the glass and tube were thoroughly wetted. Put a heatshrink sleeve on, and use the heat gun.

My issues:
1) I was led to believe there would not be any longitudinal shrinkage in the heatshrink (<1%), but I actually got >10%, so the wrap shrunk up more than I allowed for, and I was left with an inch or two on each end that didn't get wrapped. Is this typical (the shrinkage)? Do you guys normally do something to fasten down the ends of the heatshrink?

2) After removing the heatshrink, the glass weave texture is still visible on the surface. Did I squeegee too much epoxy off? How do I know how much epoxy to leave in, to get a glass-smooth finish after the heatshrink, but not too much excess weight?

Thanks,

Kelly

Your experience sounds similar to mine. I suspect a flawless glass smooth finish is somewhat difficult achieve, likely to have a spot or two if for no other reason than you get a little air trapped, a "bubble" that is overlooked. On my last tube, I did not use the wrap at all, but I had a rotisserie to turn it.



In general, I think it is a great product and will continue to use it.

 

[cwbullet]

Your experience sounds similar to mine. I suspect a flawless glass smooth finish is somewhat difficult achieve, likely to have a spot or two if for no other reason than you get a little air trapped, a "bubble" that is overlooked. On my last tube, I did not use the wrap at all, but I had a rotisserie to turn it.



In general, I think it is a great product and will continue to use it.

Nice setup. Where did you get the motor?

 

[jahall4]

Nice setup. Where did you get the motor?

Thanks, Amazon, here is what I purchased along with bracket, cord, coupling: https://tinyurl.com/25erpvw

 

[conneryc]

I used a Soller glass sleeve for the first time the other day, and had a couple issues maybe you guys could help with.

I followed the videos/info I've seen: put a couple CRs in the tube and inserted a dowel, put the sleeve on, fastened the ends. I mixed up epoxy (about the same weight as the sleeve), applied with a brush, and then used a credit card to squeegee all the excess resin out after the glass and tube were thoroughly wetted. Put a heatshrink sleeve on, and use the heat gun.

My issues:
1) I was led to believe there would not be any longitudinal shrinkage in the heatshrink (<1%), but I actually got >10%, so the wrap shrunk up more than I allowed for, and I was left with an inch or two on each end that didn't get wrapped. Is this typical (the shrinkage)? Do you guys normally do something to fasten down the ends of the heatshrink?

2) After removing the heatshrink, the glass weave texture is still visible on the surface. Did I squeegee too much epoxy off? How do I know how much epoxy to leave in, to get a glass-smooth finish after the heatshrink, but not too much excess weight?

Thanks,

Kelly

I don't use heat-shrink, just a wrap of Mylar/Duralar to get a perfectly smooth surface. I used the Soller sleeve for my 7.5" L3 project. You can see in the first picture below the setup just before applying the West Systems resin. You can also see the waiting Mylar sheet to be wrapped around the tube after the glass is completely wetted out. the other picture shows how smooth the finished tube is (left of the fins) after the mylar is removed. The duller look between the fins is from the tip to tip laminations that were done.

 

[David Schwantz]

When your removing resin using the card, if the glass cloth is still white, you do not have enough resin. If the cloth is shiny, you have to much and need to remove more. Try to have the best lighting that you can, just like painting. Helps to see the wet and dry areas better.

 

[John Kemker]

Expecting a 3" Estes PSII Nike Smoke, soon. Thinking seriously about trying a Soller wrap and heatshrink to reinforce the BT. I'll be using my Zwilling vac-bagging system for the fins.

 

[kenstarr]

I've done quite a bit of soller composites sleeve. I usually do my tubes and shrink tube oversize then cut to length as needed. I also wet sand when looking for a real nice finish. For smaller tubes I've really liked this heat shrink tubing from ebay:
https://www.ebay.com/itm/2027342265...T0gttEVR-y&var=&widget_ver=artemis&media=MORE
On my kevlar nightmare rocket I put a thin sleeve of fiberglass over the kevlar sleeve before shrinking and curing so I could sand. Still though... It was a nightmare
Ken

 

[kenstarr]

Heres my Darkstar 5 (micromaxx) carbon fiber sleeve and carbon fiber fins!

 

[Kelly]

For smaller tubes I've really liked this heat shrink tubing from ebay:

I was under the impression that the Soller heat shrink was internally coated with some release agent, and thus that "generic" heat shrink off of ebay or elsewhere might not work as well - could stick. Have you not found this to be a problem?

 

[John Kemker]

My Nike Smoke arrived today and the Soller 3" tube and 3.1" heat shrink is on their way.

 

[kenstarr]

I was under the impression that the Soller heat shrink was internally coated with some release agent, and thus that "generic" heat shrink off of ebay or elsewhere might not work as well - could stick. Have you not found this to be a problem?

That was my understanding as well. But upon experimentation I found otherwise. However, don't use the bi-layer heat shrink that has 2 different types of shrink. You would know it because when you shrink it down the inside layer looks like goo or melted glue stick.
Ken

 

[G_T]

The inside layer on those is a type of glue stick. It's purpose is to glue seal and provide strain relief. It doesn't like a lot of heat since the glue reliquifies readily enough. But it can be quite useful in some situations. I've used a lot of it.

Gerald

 

[KenECoyote]

I used a Soller sleeve and their shrink wrap today on a 6" PML phenolic tube and made sure to have extra shrink wrap on the ends. Pretty happy with how it came out.




This was my second time using the same. The first time was a few months ago on a 7.5" Loc tube and like what happened to you, my shrink wrap ended up short on one end by about a half inch.

 

[Kelly]

I'm ready to try a carbon sleeve sometime this week. Any tips for that? How do I know when it is wetted? Glass, being transparent, is pretty easy to see. I'm thinking with the CF I'll just need to add plenty of epoxy, give it plenty of time to soak in before squeegeeing out, and hope for the best.

One other question on glass - On your tube, like mine, I can clearly see the glass. But I've seen glassed cedar canoes where the glass was completely invisible. Why do our tubes look so... glass fabric-y?