Reinforcing Resin with Fiberglass?

[batninja]

Although I said I wasn't going to do it, I may reinforce my SgtFang Mystery Helmet with fiberglass, primarily since I intend to install HyperDyne's servo system into the lightweight helmet. I'm worried that the weight of the servo system might be too much for the helmet.

For those with fiberglassing experience, what should be on my shopping list? Where can I buy the supplies? What are some hurdles I might run into?

 

[evan4218]

I may be able to help ya on that... give me a buzz and we can talk about it.

 

[Devilstar2k2]

Evan,

Can you post the information that you have? I think it could benefit alot of us with the SF buckets... Know what I mean?


Thanks,

Shawn

 

[Devilstar2k2]

la la la laaaaaaaaaaaaaaaaaa...

So is it top secret, or what? Help us out Evan...

 

[ShocKWavE]

You could probably just get some fiberglass cloth, fiberglass resin (with catalyst), and a few small brushes from a local hardware store (such as Home Depot) and add that to the interior. Cut the cloth into small pieces (maybe 1" x 2"). Lay down an initial layer of resin onto the interior. Then, lay the cloth in one piece at a time. Load the brush with some more resin and tap the cloth into the resin until it becomes transparent. Overlap each piece slightly and continue the entire helmet. If there isn't much interior detail, you can probably use the weaved cloth. Let the cloth come slightly beyond the edge of the helmet and you can cut the excess off after it dries.

Use a respirator! The fumes and the dust from cutting are both very bad for you. Use eye protection! These chemicals can blind you. Use acetone for cleanup. Stay away from spark or flame. Wear gloves. Touch this stuff as little as possible, and if you get any on you, clean up right away. Also, try to only mix up as much resin as you will be using. Pay attention to the mixing ratios. You only need a little catalyst in the resin. Just be cautious and organized and it should come out fine.

 

[CombatBaby]

You could probably just get some fiberglass cloth, fiberglass resin (with catalyst), and a few small brushes from a local hardware store (such as Home Depot) and add that to the interior. Cut the cloth into small pieces (maybe 1" x 2"). Lay down an initial layer of resin onto the interior. Then, lay the cloth in one piece at a time. Load the brush with some more resin and tap the cloth into the resin until it becomes transparent. Overlap each piece slightly and continue the entire helmet. If there isn't much interior detail, you can probably use the weaved cloth. Let the cloth come slightly beyond the edge of the helmet and you can cut the excess off after it dries.

Use a respirator! The fumes and the dust from cutting are both very bad for you. Use eye protection! These chemicals can blind you. Use acetone for cleanup. Stay away from spark or flame. Wear gloves. Touch this stuff as little as possible, and if you get any on you, clean up right away. Also, try to only mix up as much resin as you will be using. Pay attention to the mixing ratios. You only need a little catalyst in the resin. Just be cautious and organized and it should come out fine.

Working outside and having a partnet will also help greatly.
One person to do the laying of the fiberglass in the helmet and one to be cutting strips and handing them to the other. It helps not to have sticky hands when trying to cut the stuff. It also helps to be outside for ventilation. Even if you work inside with the respirator on your house still has that odor lurk for awhile

-=QuinN!

 

[Honus]

If you don't want that awful smell you can use epoxy resin instead of polyester resin. You have to use woven cloth with epoxy resin as it won't work with chopped strand mat- CSM uses styrene as a binder and epoxy resin won't melt it.

Here is another product that might be just the ticket for reinforcing a helmet- it's called BolderWrap. I saw it in my local hardware store. A 10 ft. roll of 4 inch wide tape costs $10. It's a prepreg structural tape that you just cut and then place it wherever you want and spray it with water to catalyze it -it probably uses a polyurethane resin. It then drys in about 4 hours and can then be sanded and painted. I saw some samples of it and was really impressed. I have yet to use this stuff myself but I was thinking about picking some up and checking it out. If I do I'll let you guys know.

http://www.comptekcomposites.com/

The same company also makes a really awesome low foaming polyurethane glue.

http://www.bolderbond.com

 

[Devilstar2k2]

Wow... BolderWrap sounds idiot proof... I'll have to check that out.

 

[clonesix]

Pardon my ignorance, but can someone tell me what the SFMH is made of? The thread title says only "resin," and that can mean anything. Is it polyester? polyurethane? epoxy? I ask because these days, everyone uses the generic term "resin" for polyurethane casting resin. All 2-component polymers have a "resin" side (B), and a "catalyst" side (A).

So if it is made with polyester, then reinforce with polyester, and so on with polyurethane ect.

My next question is "how much reinforcing do you need?" The previous post for the "Boulderwrap" sounds like the trick, but I have never used the stuff. So I would have to experiment with it to get a feel for what it does.

Barring experimentation with new products, It won't hurt to go with the ol' stand-by: fiberglass. I reccomend FG Tape for this job. http://www.shopmaninc.com/cloth.html (goto bottom of page)
Tape is cloth with a wrapped edge that won't unravel.

2 layers of FG tape will add a lot strengh but not much weight. A couple strips down the side will give that range finder a lot of support. A coupe strips along the bottom will reall stiffen the helmet. I don't think that any is necessary in the dome.

As far as resin? 30 minute epoxy will work fine and be compatible with most materials. Its fast, strong, available in 5 oz bottles, and its quick.

Feel free to talk amongst yourselves

 

[psych0ticmisfit]

just a quick question has anyone tried making their helmet using carbon fiber instead of the fiberglass? theres really no reason to but hey it would look nice before you painted it.

 

[Honus]

just a quick question has anyone tried making their helmet using carbon fiber instead of the fiberglass? theres really no reason to but hey it would look nice before you painted it.

Well I do have a whole bunch of woven Kevlar left over from a racecar project as well as some West System structural epoxy......

 

[Hammer of Might]

Well I do have a whole bunch of woven Kevlar left over from a racecar project as well as some West System structural epoxy......

haha, a kevlar helmet. You could actually use it in battle.




but don't tell uniderth that.

 

[Hippo Clone]

i have made a f-18 crew helmet using the carbon fiber and here is what i have to say about it. carbonfiber is a pain to work with (not to mention expensive) and does not like to stick to itself. it frays easily and contours very badly. it wasnt too bad because of a nice flat surface but trying to do multiple layers. well it got very messy.

 

[Honus]

Carbon can be a bit of a pain to work with as it doesn't drape quite as well as fiberglass (it depends a lot on the type of carbon weave you use) but I've never had any problems wetting it with resin and getting it to bond well but I tend to vacuum bag carbon laminations whenever possible. You also need to wear rubber gloves when cutting it as little carbon slivers can get in your hands and can be a real bugger to get out. If you bond it to Aluminum you need to use a fiberglass layer as an insulator otherwise the you'll get a galvanic reaction and the joint will delaminate over time, especially if you live in a coastal environment.

Kevlar on the other hand is a real pain to cut (you have to use ceramic shears) and the ends of the fabric get kind of fuzzy. It's also much harder to wet out.

I made some quick carbon fiber modifications to the nose section of a Mazda Ralt R5 CSR sports racer so it could clear bigger/wider tires. It was a fun little project- the car has an Aluminum monocoque chassis and has around 200hp and weighs about 1300lbs. It's like a big go kart.

 

[kanol matea]

where in home depot is the fiberglass cloth and the resin becouse nobody at my local lowes know anything about anything help would be well be very helpful

 

[ShocKWavE]

It is usually near the paints and glues.

 

[drcrash]

Has anybody tried the BolderWrap yet?

About that, or about epoxy or polyester fiberglass...

Is there a problem with shrinkage and warping?

I'm considering vacuum forming some stuff with deep draw and little draft. (Undercuts, actually.) If I manage to vacuum form it at all, the plastic will be very thin in places, and need reinforcement.

I'm wondering if polyester FG would shrink too much, and if so, would epoxy be OK? (Epoxy shrinks less than polyester.) If the polyurethane prepreg is easy and doesn't shrink much, that might be even better.

Any advice wold be welcome.

 

[drcrash]

Poking around on the net, it seems there are several brands of knitted fiberglass reinforcement tape pre-impregnated with moisture-activated polyurethane resin. Some are sold as plumbing repair tape or for marine repairs. I'll have to look into that more.

 

[drcrash]

After more poking around, it seems that some muffler repair tapes work the same way---water-activated polyurethane impregnated fiberglass. (Others aren't, though.) I don't know if those require heat to post-cure to full strength, but at least some are supposed to set at 60-80 degrees F.

 

[drcrash]

I just recently noticed that my local Lowes has DuraBond (I think) Pipe and Hose Repair Tape for $10 a package, where a package is one vacuum sealed foil pouch with a 5-foot roll of two-inch tape. (Or maybe it's one inch...)

The DuraBond stuff seems to be one of at least a half dozen brands of moisture-activated polyurethane prepreg knitted fiberglass tapes sold as "Pipe and Hose Repair Tape" or "Pipe and Hose Repair Kit" or various similar things.

I also noticed that my local Pep Boys has several seemingly similar things, sold as muffler/pipe and/or hose repair kits. One of those only costs $3 for a package. (Which I think is one inch by five feet.)

Unfortunately, it's not clear which of those require muffler heat to cure, or to fully harden by "postcuring." I may try the cheapest one or two anyway.... seems likely they'll cure, just more slowly without the heat, or may not ever attain their full strength but still be strong enough.