Tutorial: Using Bondo for Detailing

[charlie tuna]

is primer that black stuf that you spray on to see wat details you missed or is it like bondo ?

Yep, primer is a base coat of paint used to prep surfaces for the next or final coat it's also used to show scratches, minor gouges, pits, dents or other defects in the surface you're working on, sand some more or fill the deeper defects, then prime again to see if you got them all.
btw, grey primer shows up surface defects better than black.

 

[pinkmasterchief]

hey thanx but i prefer black......caus i think it looks kewler

 

[Ral Partha]

hey thanx but i prefer black......caus i think it looks kewler

It's going to get covered with paint anyway so choosing a primer based on its color doesn't make much sense.

 

[pinkmasterchief]

i meant for the color of the helmet. like putting silver to make it more -flashy-

 

[Spartan HJD]

is primer that black stuf that you spray on to see wat details you missed or is it like bondo ?
Primer is a spray paint that you can spray on to see missed details. It is mostly used just to make paint stick better. It is not like bondo at all. hope this helps.

 

[dozver12]

i am going to bondo my helmet soon and i was wandering what sanding method is best and if there is a signifigent difference between wet sanding and dry sanding.

 

[b0anerges]

I'm moving into the bondo step on my helmet. From looking on the threads I've seen tonz on different ways to do this. Sometimes people cover the whole thing and loose the detail in the helmet.

Is the Bondo process an important part to adding strength to the helmet? I just was to add bondo to the parts of the helmet that have the polygons. Do I need to bondo the whole thing for strength?

I'd like to hear some opinions on this. Thanks

 

[harleyb14]

how do you know where to sand? it covers all the details? sorry, just makes no sence to me, ive never done anything like this before. and if you sand it down back to the cardboard, wouldnt all that work be pointless? haha, im so confused. sorry

 

[swampbilly]

how do you know where to sand? it covers all the details? sorry, just makes no sence to me, ive never done anything like this before. and if you sand it down back to the cardboard, wouldnt all that work be pointless? haha, im so confused. sorry

if there is a low spot in your piece that needs to be raised just a little higher or maybe the edges are too square bondo adds in the chunk that you need. in picture one it shows a low spot on my helmet...so in turn i need to raise it. in image 2 i spread on some bondo to fill it in....(mind you these pictures arent of the same point on the helmet). in image 3 the spot low spot that was filled in has now been sanded to the angle and shape i want it to have.....kinda like hard clay in a way. i shape it how i want it....get it? let me know or anyone else for that matter is more than willing to help.

 

[BFDesigns]

usin' a damnedable rubber spatula to spread the bondo out. worked good for the top part of the helm but the bottom part is kinda trailin' cuz of all the detail. Dremmel tools help a ton kids!

by the way: does anyone know where i can get gold automotive tint for less than $40 a roll?

 

[BFDesigns]

also, i've found that Great Stuff works great in filling the many cavernous spaces that the torso has. One can will definitely fill the torso and the great thing is that it will expand towards the path of least resistance, meaning that it will not warp the fiberglassed cardstock! you can sureform it after is is fully hardened and cured to make a space big enough for you to fit inside, trust me, this stuff really works and it'll add some body to your armor so that you actually place the bondo onto a solid foam form instead of just a hollow paper form. I would not reccommend it for anything other than the biceps, handplates, or torso, but it probably will work for anything... it'll just be a pain in the ass to sand the inside of the closed forms. Remember: FIBERGLASS YOUR FORMS BEFORE YOU FOAM THEM!

 

[master chief403]

So when I first started i didnt really have any idea how to use bondo, now that I do, i figured I'd make this tut for you all incase some noob like me rolls around with the same question!

How to mix bondo body filler:

Get a FLAT clean surface made of plastic or metal (plywood is not acceptable).

Scoop a 4" diameter dollop of filler onto the surface.

Squeeze out a 1-3" line of hardener. A 1" line is what is called mixing the putty "cold". This means you will have more time to work with it, but it takes considerably longer to dry. If you use too little hardener it will never dry and will always be sticky. If you use a full 3" line of hardener you will be mixing it "hot" This will give you quick drying times and a very hard finish. Unfortunately it will be more brittle than mixing it cold. 2" is the median and is what I would recommend.

Using a putty knife, fold the hardener vigorously into the putty so that it is mixed evenly. Don't take too long doing this or the filler will begin to harden while you are mixing.

Now carefully apply a generous amount of putty to the area you are trying to fill or shape.

When the putty is hard but can still be dented by your fingernail use a small Sureform file to roughly shape the putty. You can also use some 80 grit sandpaper for this.

Now allow the putty to cure completely. When cured it will be hard like plastic, and will be giving off no heat.

Now do your final forming with some 360 grit sandpaper, elbow grease and finish it up with 1200 grit for painting.

hope this helps someone!

thanx

 

[BFDesigns]

the best thing to use for spreading bondo quickly and evenly at a respectable thickness is to use latex gloves. simply mix up a helluva lot of bondo (cold working method), slop it on your large parts with a spatula, and use your hand to spread it around. a mighty mouse sander also works incredibly well and saves time for detailing.

 

[BFDesigns]

does anyone know what the difference between pink bondo & gold bondo besides price?

 

[mothergoose]

thanks, there was some really detailed info here, im sure this is gonna really help once i get there

 

[Rhith]

Great thread, giving me hope that I can do this after all!

 

[agroom]

also, i've found that Great Stuff works great in filling the many cavernous spaces that the torso has. One can will definitely fill the torso and the great thing is that it will expand towards the path of least resistance, meaning that it will not warp the fiberglassed cardstock! you can sureform it after is is fully hardened and cured to make a space big enough for you to fit inside, trust me, this stuff really works and it'll add some body to your armor so that you actually place the bondo onto a solid foam form instead of just a hollow paper form. I would not reccommend it for anything other than the biceps, handplates, or torso, but it probably will work for anything... it'll just be a pain in the ass to sand the inside of the closed forms. Remember: FIBERGLASS YOUR FORMS BEFORE YOU FOAM THEM!

This is exactly what I was looking for here, thanks! I'm about 2 pieces done with creating the card stock shell and moving onto the fiberglass/resin step. But my big question is filling in the hollow places. My primary concern is the bill for the helmet (doing the Mark V), the way it sticks out so far and is completely hollow. I feel filler like this is almost necessary to help from crushing it. There are other similar areas such as on the shoulders with similar issues too. I'm sure after the strengthening process it'll be okay, but I'd feel better if those cavernous areas were filled with something.

So 2 questions:

1) You only recommended the torso and bicepts and hand plates, why? I'd planned on filling in most "insides" of every piece. One I think it'll help strengthen some, but mostly I think it would help contour the body for a better fit and give it a more full look.

2) How easy is it to mold/detail once hard? I'd planned on putting more filler than needed and cutting back until I was able to fit inside easy.

 

[Canadian42283]

nice post. i just started my bondo work today and it helped alot

 

[Voxic21]

hey im about to start the bondo and i was woundering do u do the inside to? also how do you do this part exactly im really confused? do you apply it to the entire helmet then sand and detail or what??? someone help plz..

 

[Kissker]

bondo is originally created to fill Automotive dents and damage to cars like that - it's made to go onto large , reletively flat or simple curve surfaces, then to be sanded crazy smooth for painting (when done right - you won't know there was a dent by sight)





Bondoing costumes is not really used inside the suit (inside the helmet etc) unless you MudGlass it (mix of bondo and resins)



Your first batch - will be incredibly messy. Bondo is sticky, super sticky, it likes to stick to EVERYTHING, in fact I don't know what it doesn't stick to while still "workable".



You CAN use your hands to work it.. however... this isn't adviced.. besides possible toxicity of the bondo itself, while it cures it heats up, increadibly. Although in small bits it will just be "uncomfortably hot" and shoult not leave any scars/blisters or anything like that. I worked it with my hands on another project, after it cures nearly completely it just flakes right off of skin, still warm to touch and slightly flexible.



I would not recommend using a 3inch line of hardener and your hands - this will simply be too hot to manage.



I suggest working in small amounts, even a 2inch dollop and a 1inch line of hardener, and a test/scrap piece (maybe a knee piece that didn't quite come out right or something) to try it first. Youll want to put "too much" on at first, then scrape off what you really don't need, and follow this tut, its pretty good.



Sanding is the only real tedious work - and you SHOULD WEAR A MASK when you do it, no matter if your indoors or outdoors. The dust particles are bad for your lungs. (as are most)