Saturday, June 8, 2013
Painting PVC Pipe
Just during the past week, someone came to this blog after a google search dealing with "how to paint PVC". This is indeed a good question, so I thought I'd briefly touch on this topic.
Can PVC pipe be painted?
In a word - yes. That said, surface preparation is critical, as it is with painting anything else. There are also some other small but important details to keep in mind when doing this:
1) The surface MUST be clean of all oil, dirt, dampness, etc. or any coating you use won't adhere properly. I typically do this with rubbing alcohol and a clean rag.
2) The surface should be lightly scuffed with steel wool or a very fine grit sandpaper - such as 600 grit or finer. Once you sand or steel wool the pipe, CLEAN it AGAIN with more rubbing alcohol and a clean, lint-free rag.
3) Use a paint designed for PVC. If you don't, you will be disappointed. More on this below.
4) Good spray can technique applies here - use several thin coats rather than one thick one to avoid runs and drips. Also, spray with the can 10" or a foot (30 cm) away from what you are painting. Keep the can moving so you don't build up too much paint on one area. If you haven't done much spray painting, practice on some scrap first before doing your critical work.
Coatings for PVC:
Years ago, I attempted to apply a cammo paint job to an antenna mast I built from PVC pipe for my homemade portable QRP ham rig. I used either Krylon or Rustoleum - I don't remember now. The paint job looked beautiful when freshly done, but proceded to flake off whenever the pipe was bumped. I could scrape the paint off easily with my thumbnail.
Since then, Rustoleum has come out with a primer that works on PVC and some other plastics. Krylon, if I remember right, has come out with a small assortment of colors that work directly on plastics, including PVC - no primer needed. The trouble with the Krylon product is the color selection for their plastic paint is, in my opinion, rather limited.
By using the Rustoleum primer as a basecoat, you can use whatever color you want from their standard line of spray paints. I actually used Krylon's flat "Hunter Green" paint on a 50 caliber blowgun I'm making for a friend. The base coat was Rustoleum primer for PVC. It seems to have worked OK so far. A few accidents here in the lab while handling the pipe don't appear to have caused damage. See the photos for the products used as well as the blowgun.
1) I have not, to date, subjected any of these painted surfaces to severe, real-world testing yet. What I can say is that casual handling and occasional droppage against other objects hasn't apparently caused chipping or scratching. So compared to the antenna mast described earlier this IS a huge improvement.
2) ANY time one applies a solvent-based coating to PVC or other plastics, the base material is weakened somewhat. One should take this into consideration if one decides to use any kind of paint on something like a PVC archery bow that is subject to significant stress during use.
Hope this information helps someone. Have fun and stay safe.