"Help!" for: Fiberglassing, Resin, & Bondo

[Spartan1313]

I am going to be doing this for the first time, and I have a couple of questions about the fiberglass and the bondo process.

1) How thick can/should I make the fiberglass layers?
2) How many layers of resin can/should I apply?
3) I know the bondo is supposed to be applied thinly. However, I have a few flaws/detailing things I want to add into my helmet. Is it ok if I apply some extra thick to certain areas to enable this?

 

[Fireryne]

@Spartan1313

#3 Apply several thinner layers to make the thicker one IMO you can detail it as you build that area up. Also if you detail as you build you dont have to spend hours working on that one spot.

 

[Jason 078]

The best way of doing the bondo is actually demonstrated by Cereal Kill3r in his youtube vids. Light layers and use a razor blade to take care of it after it starts to cure (when it is still warm and soft).

 

[Ghost Bear 027]

I am going to be doing this for the first time, and I have a couple of questions about the fiberglass and the bondo process.

1) How thick can/should I make the fiberglass layers?
2) How many layers of resin can/should I apply?
3) I know the bondo is supposed to be applied thinly. However, I have a few flaws/detailing things I want to add into my helmet. Is it ok if I apply some extra thick to certain areas to enable this?

I agree with both posts above. The helmet will feel strong when you handle it, I think it was only about 2 or 3 coats for me with the fiberglass slapped in the middle. Another thing you can do to build up a specific area, is to make a mold of what you want to add, pour that, and attach it later to the original. You can make a nice RONDO pour happen pretty easily, and once again, use a straight razor to slowly shave out the details.

I actually recommend the Heavy Duty Utility blades by Stanley with "BOSTITCH" written on the small package. They are stronger and have great angles on the sides to help carve and scrape away at the underside of things. One of those will go a LOOOOOONG way.

 

[Revenant1988]

Hey guys,

So I started to work on filling my imperfections and pin holes and I'm not having much luck with spot putty. I must be doing something wrong and could use some tips or advice if anyone here would be so kind.

The problem

So,

I take my putty and apply a reasonable amount to fill a pin hole or other small gap.

Then I smooth over it with a spreader.

The hole appears to be filled. I wait several hours for the putty to dry and cure.

I take high grit (fine) sandpaper and begin to sand away the excess putty I don't need

At this point, the putty that was in the hole or gap just pops out, re-exposing the hole.

I'm not sure what I'm doing wrong. I don't think I'm using too much force or an incorrect motion. The area around the hole is as smooth as butter but the hole just comes back, like the putty just covered the top but didn't penetrate the hole or fill it, or its getting pulled out (??) somehow.


What am I doing wrong? Any advice is GREATLY appreciated!!

 

[Katsu]

I gave my answer on the original post you made. Hope it offered some tip.

 

[orange juice]

hey guys, i could use some help. i have a chest piece ive been working on and i rondo'd it up and started the bondo when i realized that the entire form at some point became twisted. either it got too wet or during the rondo drying process it just warped it. anyone have this issue before and know of any fixes? so far my idea is to cut it at a joint type area and tape it back where it would be straight then bondo it from there to give it structure. any thoughts or tips would be great. thanks

 

[Ragnar]

Hey guys,

So I started to work on filling my imperfections and pin holes and I'm not having much luck with spot putty. I must be doing something wrong and could use some tips or advice if anyone here would be so kind.

The problem

So,

I take my putty and apply a reasonable amount to fill a pin hole or other small gap.

Then I smooth over it with a spreader.

The hole appears to be filled. I wait several hours for the putty to dry and cure.

I take high grit (fine) sandpaper and begin to sand away the excess putty I don't need

At this point, the putty that was in the hole or gap just pops out, re-exposing the hole.

I'm not sure what I'm doing wrong. I don't think I'm using too much force or an incorrect motion. The area around the hole is as smooth as butter but the hole just comes back, like the putty just covered the top but didn't penetrate the hole or fill it, or its getting pulled out (??) somehow.


What am I doing wrong? Any advice is GREATLY appreciated!!

Did you clean all of the dust dirt and oils from your hand off the area befor adding the putty if its dirty it might not adhere well

 

[Rookie425]

Quick question. I just finished the pep stage of Vrogy's Halo 3 Marine design and I started the resin stage. Figuring I could solidify the whole thing, I layered the outside with a thin film of resin, let it cure for about an hour, and then went to resining the inside. Four hours later, the helmet was dry with a waxy texture, an upgrade from the previously touch-tack feel.

It's a little bit, but then again it's kinda light since I haven't fiberglassed it yet, and once I use the Bondo filler, I can expect the space to be taken care of. My only issue is that despite it being essentially fully cured, the resin's smell is still there and relatively noticeable.

First: Is this indicative of potential for residual toxicity on the resin?
Second: After I'm done fiberglassing, should I wait until the smell is gone before I Bondo the helmet and finalize?

 

[RobotChicken]

Mine smelled after it was dry to the touch so I left it outside in the sun all day to fully cure. By evening it still smelled a little but not much. A few days later it had no odor at all. I applied Rondo to the inside the day after adding resin to the outside. It was tacky for the whole day but now is fully dry/hard and has no odor. I don't think the residual smell has anything to do with whether it's hard enough for finishing, but since I'm not in any rush I decided to let it fully cure rather than trap the dissipating vapors under layers of Bondo.

 

[AmitKer]

Please help me!

I was hand-sanding my first pep project on my roof for a long time (about a month) without a respirator... Should I be worried?
Is bondo carcinogenic? Is it toxic to breathe? Is hand-sanding less dangerous than regular, electronic device sanding? Am I going to die (I can't DIE! The con is in the next week!)?
I bought now a respirator for my next project... But what about now?

Please answer quickly, and sorry for my misspellings (if I had any). Thanks

 

[RedGhost]

You gonna die so damn hard unless you get an lung and blood transpant.

Joking! It is not so hasardious whem sanding unless it comes in your lungs, as it did. Well, maybe you'll be sick a couple of hours, maybe a day. You'll cough hard, and maybe feel a bit nuseau. But you won't die unless it was in big quarantees(whole suit), because that has enough posion to do some serious damage.

Visit your family arts(house arts? Personal dockter?) because my expetation may be wrong...

 

[Rookie425]

Amit, I wouldn't be too worried about your condition in such short term exposure, but I wouldn't make a habit of disregarding Personal Protective Equipment either. Resin isn't the best thing to breathe in as longer term exposure can cause particles to cling inside your lungs, possibly causing things like fibrosis. I didn't know this before, but Cereal Killer cautioned in one of his tutorials against things like talc as well as it can "cement up" in your lungs, but as far as I've seen with armor making, it's nothing we're going to be working with.

On that note, I have a question for the veterans.

As said earlier, I've been working on a Halo 3 Marine build, and since I want to make this thing last, I plan on reinforcing the living hell out of it as best as I can. That means I'm likely going to be filling every inside corner of it with the fiberglass/resin combo. I have no problem sanding at all. I made some mistakes with edges in the pep stage, so I'm getting used to it. What I want to know is would it be ill-advised to add a layer of RONDO to the inside of the helmet after it's been resin'd and fiberglassed?

I'm hoping that, in addition to reinforcement, this will provide a smoother inside texture that'll require a little less sanding, as well as take up some of the empty space before I add padding. What do you guys think?

 

[Carpathia]

What I want to know is would it be ill-advised to add a layer of RONDO to the inside of the helmet after it's been resin'd and fiberglassed?

Actually, I would advise you to slush a layer of rondo before you add in the fiberglass cloth.The rondo layer will fill in all the fine details in the pep the could be left void with fiberglass (causing a hollow point) and provide a nice smooth surface for you to efficiently apply your fiberglass cloth, which, if you do it right, there should be no sharp edges. If you glass first, then rondo, the rondo won't cover any sharp edges that may form. If you do end up with sharp edges after the glassing stage, you can always knock them down with a dremel sander.

 

[Rookie425]

That's pretty informative, thanks. My reasoning behind rondoing after the fiberglass matte/cloth stage was to cover the fiberglass itself and not have to worry about it, but that makes a little more sense I guess. There ARE some holes in the pep currently, so I'll be adding a few more layers of resin before I get there. If not, then tape will always do nicely I suppose.

 

[Ghost Bear 027]

Rookie 435 - Rondo has a tendancy to chip if you drill into it, causing it to flake away a bit (at least mine has at times) but overall I would say that adding the extra layer is advisable. Primarily to smooth the inside out for when you add padding or whatever to the inside of the helmet, and to cut out those weird edges both sticking into you head and to prevent any breakthroughs while sanding the outside to shape it. The reinforcement is a good thing too.

Amit - I've got an uncle in the family who developed bladder cancer because he worked in manufacturing up here and apparently the chemicals in resins and plastics he worked with can contribute to that. I always wear my protective mask and gloves whenever I handle any of the chemicals, and I'd recommend the same to all others. Short term it's probably not going to give you a chemical burn or anything, but better safe than sorry in the long term.

 

[RobotChicken]

There is hazard and safety information printed on the containers for a reason......

 

[Rookie425]

So what I'm getting from two opinions is that I SHOULD Rondo first. Now that I've researched it in better detail, I understand why. What I want to know is fiberglass matt a good idea after the inside has been Rondo'd? I want to make this thing to last as I don't plan on molding it (a project for a more experienced time), but I need to know if Rondo and Fiberglass combined is going to be unnecessary overkill or if it would coincide with padding. Would an extra layer of Rondo be a better alternative?

 

[Katsu]

I always do a thin layer of rondo inside first, then lay fiberglass mat/cloth over it, and then do a VERY thin layer of rondo over that (to cover the fiberglass which can be prickly).

The first rondo pour backs the pepakura so you can drill into it, and also smooths the interior so you can lay fiberglass evenly. The fiberglass is the main strengthener as JUST rondo is risky (it can crack if you drop it), and the last rondo layer is to smooth the inside.

 

[RobotChicken]

The plan for my pieces is to Rondo the inside first to provide a smoother surface for glassing and to give a little thickness for avoiding punch-through when filing down edges on the outside. Fiberglass mat has the glass oriented in random directions instead of an orthogonal weave (making it stronger than cloth), but I've read that the strands can separate when they get wet with resin during application and that they tend to lift with the resin brush resulting in a "prickly" surface inside. Since the cloth is woven I expect that effect to be less, but because it's woven it won't conform around corners as well as mat. Thus the layer of Rondo first, to reduce the sharpness of pep corners (and to fill small crevices that would be impractical to glass).

Rondo is heavier than fiberglass and also is brittle (prone to cracks and chips) so I'm not relying on it as the sole hardening medium. I will be adding two overlapping layers of glass over the Rondo for the strength that Rondo alone won't give. (I've read about dropped helmets that have cracked due to hardening with Rondo only.)

I was initially planning to finish the inside with a thin layer of Rondo over the glass as Katsu said, but after realizing just how much difference there is in weight between glass and Rondo I've decided to skip the last Rondo layer. All the pieces will be padded inside so in my opinion the padding itself is enough to cover the prickles, and the roughness of the glass layer will help the padding (or velcro if I decide to make the padding removable) adhere better.