Bondo and Spot Putty Questions.

[chaff14]

Hello everyone, I'm making my very first ODST helmet, and it's coming along nicely. I just have a couple of questions about bondo and spot putty.

1. Why do you need to sand down your helmet, then reapply bondo and spot putty, like in this video. Couldn't you just put spot putty on it and repaint it?

2. I can't find spot putty (I'm canadian), but I found this. Is that the same stuff?

3. How sandable is bondo? I'm thinking of putting the bondo on as best as I can, then just sanding what I don't want off. Would that work or do I have to pretty much get it prefect the first time?

Thanks for reading. If any of these questions have already been answered, just leave a link.

 

[amancue]

well to sum it up in a few words, this stuff IS Bondo, its just made to be UV proof, not be ruined by extreme sun, 2) spotputty isnt hard enough, even fully cured its still no where remotely as hard as bondo
though this http://www.canadiantire.ca/AST/browse/4/Auto/AutoBodyRepair1/AutoBodyFillers/PRD~0475625P/Bondo%252BLight%252BBodyfiller.jsp?locale=en
is more what your looking for when it comes to bodyfiller and its cheaper this is spot putty, you should be able to find it in some autoparts store OR walmart
http://www.jamestowndistributors.com/userportal/show_product.do?pid=5966&googleaffiliate=

 

[Boba Fett]

Spot putty is hard, it's just brittle. It's a micro-filler. Regular bondo may leave imperfections, not enough applied, etc. Instead of mixing up a bib batch, just use a tiny bit of spot putty for flaws.

 

[Kirrou]

The best method I have found is to apply a relatively thin layer of bondo and then sand it back down. But even if your good with bondo, it will still sometimes leave little holes.(usually caused by air bubbles) These you will want to fill with spot putty to get everything perfectly smooth.

If you where to use spot putty over a large surface area, it would crack and chip. Large chunks would fall off because spot putty isn't as strong as bondo and like the others side it is very brittle.

I also recommend getting a mouse sander(just google it). Even a cheap one will work. I got mine for $15 at "Harbor Freight" which is a very cheap hardware store here in the US. But you can find them in most hardware stores for about $30ish dollars.

 

[paradoxdj]

yeah sopt putty is for minor fixes. you can find it in canada, it's called glasing putty, made by bondo as well, at canadian tire or auto value auto parts.

 

[chaff14]

Thanks for all the answers guys. I looked online, but I still can't find spot/glazing putty. Would using a small amount of Bondo work to fill little holes and cracks too? It might be more hassle, but it might have to do.

 

[Kirrou]

Thanks for all the answers guys. I looked online, but I still can't find spot/glazing putty. Would using a small amount of Bondo work to fill little holes and cracks too? It might be more hassle, but it might have to do.

Yes you can. I found that if you need to fill pin holes using only bondo that you can but only when it is beginning to cure. Then it can act much like spot putty.

So say for example you are bondoing you helmet, and in some areas you got some pin holes. Wait for those areas to completely dry. Continue adding bondo to other areas that need it, but when you have a little bondo left, right as it begins to cure, you can go back over the areas that had pin holes and with a good amount of pressure fill those holes with bondo.

When it begins to dry bondo can have the same qualities as spot putty. But only in very small quantities so that is doesn't get chuncky and only when you apply a lot of pressure.

 

[skylow]

Thanks for all the answers guys. I looked online, but I still can't find spot/glazing putty. Would using a small amount of Bondo work to fill little holes and cracks too? It might be more hassle, but it might have to do.

For cracks and pin holes and air bubbles holes i use gap filling glue like this. its gel like and sand-able when dry