Tuesday, June 3, 2008

Fuse block and Krider Blue Test

Another stupid rain day but I tried to make the best of it. I seem to have a little dark rain cloud following me around the days I want to paint!

Two weeks ago, while chatting with other R2 Builders, the topic of electronics came up. I learned a good deal, since all I really know is not to stick anything over 9 volts on your tongue. The topic of grounding came up and some of the people there made some great suggestions. One link they shared was a maritime electronics dealer. Since boats have similar 12 volt systems, what they use would suit an aluminum robot well too! A fuseblock they had good things to say about was this one: http://bluesea.com/category/5/21/productline/126 As it turns out, being in a very maritime state like Maine, I had a local dealer 25 minutes away. I saved $10 plus the $14 I would have had to pay for shipping.

The only thing it doesn't have is labels, but the box gave the exact dimensions, so I can use MS Publisher or the sort to custom make and cut my own. I also picked up a few 10, 20 and 30 amp fuse blades.

With that done on Monday, I focused on Tuesday being paint day.

I bought a cheap wooden clothes dryer and thought it would be ideal for hanging or resting parts on. I unravelled an old wire clothes hanger and hung up my two test pieces, a set of Keith Henry's resin utility arms.

I gave them two coats, 15 minutes apart, of Duplicolor White Primer.

After reviewing the YouTube videos of Mike Senna painting with the Krider Blue method, I shook the Rustoleum Purple and started lightly spraying. (I opted to lay the pieces on top of the rack since they will be seen frontwards-on and not be actuated anyways. Plus, if these go badly, acetone time!)

Not long after, I began to see these tiny bubbles...

After waiting the prescribed 15 minutes, it began to pour outside. Ugh! The first rule of painting is not to paint when its humid out. Rain means 100% humidity! What to do? Well, heck, go for it.

So on went the Duplicolor Anodized blue.

...and then it started to turn an off-white color. I suspect the paint wasn't adhering well because of the weather. And again, the bubbles persisted.

Feeling a little discouraged but none-the-less committed at this point, I put on the first coat of clear 30 minutes later, hoping the additional time would give the paint more time to dry better. It did seem to look a lot better after the gloss went on.

I figured if drying was my issue, perhaps I should do the oven approach Mike Senna did in his video. Mike's oven is gas, so he has a pilot light already keeping the oven at 90 or so degree. Mine's electric so I set it to pre-heat up to 250 degrees. When it got there, I shut it off.

I went back to the garage, hit one last coat of gloss on the arms, then brought them inside on top of some scrap wood. I put that in the oven, with the door open for 30 minutes.

Here's the result after it was done...

A few things to note...asides the imperfections in the resin parts (divots, etc that I didn't fill in), the color looks really good. I'm a bit mystified about the bubbles on the top arm still, but again I think moisture had a lot to do with it.

I think when I do this again, with better weather, I'll do the oven bake portion to enhance drying. But the color scheme works. As others have commented, it doesn't photograph well at all, because it has this odd glitterly sheen to it that's just perfect.

If you'd like to see the video tutorial videos that Victor Franco has created, they are here:

Part One: http://www.youtube.com/watch?v=b-amGvvYbzg

Part Two: http://www.youtube.com/watch?v=5ZuaxsLl7Sg

1 comment:

  1. The issues with the surface bubbles you mention are due to a phenomenon referred to as "out gassing" of the resin material at a chemical level; nothing to do with humidity.

    This is common if the resin piece has a large mass, and/or the maker did not: Use a good quality resin, 2.thoroughly mix, 3. use "virgin" mixing containers or 4. accurately measure the liquid resin ratios.

    Polymer/resin out-gassing normally subsides after 1 to 1 1/2 weeks after the piece has been demolded and allowed to air-cure (This can vary depending on the resin brand used and maker accuracy).

    Unfortunately, as an end user all you can do is make sure the part(s) is/are thoroughly washed (warm soapy water)and completely dry FIRST - before any primer is applied. Prime, cure, wet-sand then prime again.

    For a piece like this, I would recommend a minimum of 3 primer coats. Also, any application of a "clear coat" over base pigment should always be done ONLY when the base coats have thoroughly cured post baking- (usually 72hrs). I do not advocate using your home oven to cure-bake...be aware noxious fumes are released during baking/curing and can leave harmful residue. Use a dedicated oven specifically for this purpose - NOT one you intend to use for food. Hope this helps,



Thanks for your comment...due to problems in the past with spammers and other abuses, all comments have to be screened before being published.