Geologists travel near and far in search of rocks. We measure sedimentary bed dip, record structural data, and collect samples. Lots of samples. This summer during my Namibian field season I collected 70.3 kg of rock samples (which is considered a light load), some small some large. The geologist is then faced with the problem of getting the rocks back safely to our home institution. Partly this is running around town acquiring the necessary export and shipping permits. The other part is packing the samples to ship. Geologists all have their own methods. I would like to share mine. I was indocturated with the CRowe method of sample shipping.
Here we’ll be packing our samples in used paint buckets and securing them with a silicon foam.
Materials and Tools Needed
- Large paint buckets (used can be acquired for free or cheap. New is $$) with lids
- Black heavy duty garbage bags
- PU-Foam (silicon foam)
How to pack your samples
- Place the sample in a black heavy duty garbage bag. Only the heavy duty black bags will work in the case. Lesser bags will be dissolved by the PU-Foam. Several smaller samples may be placed together in the same bag. I usually pack no more than three samples in the same trash bag. Close of this bag and wrap excess bag around itself. Place it in the bottom of the paint bucket. Repeat until you have a layer of rocks on the bottom of the bucket.
- Shake shake shake that PU-Foam can. Install the applicator straw. Be very careful to not get any foam on you when packing samples. It’s hell to clean off. The only effective method of removal seems to be acetone. Some PU-Foam cans come with plastic gloves, but these can be annoying to use, so best just be careful. Apply the PU-Foam to gaps between the samples and the bucket wall. The foam will expand, but no reason not to apply liberally.
- Wait for the foam to set. The PU-Foam cans usually recommend waiting 2 hours or more. This is a tad long, but the more time the foam has to set before adding the next layer the better. If the foam is not allowed to set fully, it will morph into a sticky ooze. For this reason I will pack multiple buckets at the same time.
- Now that the layer has set. Repeat steps 1-3 until the bucket is full. Don’t forget to let the foam set between layers. Relax, have a beer while you wait.
- Now we’re going to seal up the bucket. Slap the lid on and use a hammer to bang down the lid’s side tabs. Be sure the lid is totally secure and doesn’t spin. Finish off the bucket by going around the lid with duct tape.