using multi-etch

Plastics to use with Multi-Etch

We often stress the importance of using and storing Multi-Etch in plastic containers, never in metal or glass. First time users will receive dry Multi-Etch powder in a plastic gallon jug. This jug is meant to have distilled or deionized water added to make a gallon of regular strength or 1/2 gallon of double strength Multi-Etch. You can pour 150–160°F water into the jug to mix the solution.

multi etc h in white plastic buckets.jpg

When using heated Multi-Etch in either a double boiler or in a custom tank, there are a number of types of plastics that can be used. For small users (one gallon or less,) you can find suitable plastic containers at big box or grocery stores. Look on the bottom of containers to see a number inside a triangle. Most of these containers will have a number 5, for polypropylene. These can withstand up to at least 212°F.

5 recycle symbol

For those of you building your own containers, several other plastics besides #5 can be used:

#2 white polyethylene can be heated to 160°F. This is what our Multi-Etch jugs are made of.

#3 PVC--upper thermal limits are 140°F for type 1 and 158°F for type 2

#7 is usually polycarbonate and can be heated to 212°F but #7 does include other plastics so sometimes means a type other than polycarbonate.

If you will run larger tanks of 5-20 gallons, we recommend IPEC Global who can construct complete customized systems which can include tanks for cleaning, rinsing, Multi-Etching, rinsing, and anodizing. 

Check them out here and see videos of their systems here.

We welcome your questions and comments about plastics compatible with Multi-Etch. Click here for our video which describes containers used with double boilers.


Multi-Etch Answers Customer Questions: December 2019

Long time friends, Bruce and Christine Senchesen, who are new Multi-Etch users sent us the following questions.

Bruce and Christine Senchesen with a display of their wall art behind them.
  1. My start setup will be the crock pot deal. How critical is the temperature if it varies within the 120–160°F range?

    Answer: “The temperature range is not critical. In fact, you really do not need a thermometer at all if you're using fresh etchant. Upon heating the solution you'll notice, as it heats up, a fine bloom of bubbles. Use that as an indicator of when to etch. But you won't see the bubbles if you reheat the same bath so it would be helpful to time the heating when you're using fresh etchant so you will know how long to heat if you reheat the same bath.”

  2. Also, your instructions call for a non-metallic thermometer. I can't seem to find one.

    Answer: “I actually use a metal probe type thermometer, Ashcroft 0°F - 220°F, available at Hardware stores. I use it for spot checking the temperature and it's OK that it's metal if you are just spot checking. Some companies leave thermometers in their bath all the time and in those cases, a non-metallic probe is required.”

  3. I loved the bite from HF to erase scratches and was wondering if I took the pieces to be sandblasted, what material would be best to get similar finish before Multi-Etching?

    Answer: “The bite is not like Hf--it will maintain whatever finish is on there unless you etch more than 3 minutes. Blasting with glass beads, wire brushing, belt sanding (which makes the ti resemble nb in brightness,) scotch pads, etc. will all be helpful. I've never tried blasting with ‘sand’ so, not sure about that. I like the coarse glass beads, 40-60 mesh.”

    Added note: Do not blast with aluminum oxide; it will prevent good color. Similarly, if you use wire brushing, be sure to thoroughly clean with Simple Green before etching.

Check out some examples of Bruce and Christine's beautiful work!

Check out some examples of Bruce and Christine's beautiful work!

Have more questions about Multi-Etch? Feel free to send them our way! Please email or join our Facebook Group and share your questions and feedback.

Using Multi-Etch Heated and Unheated

Ever since we developed Multi-Etch in 1993, we have always used it heated because it is much quicker than using it at room temperature. Recently we conducted extensive experiments to compare the efficacy of heated vs room temperature. What we discovered is that over time, whether heated or unheated, unused Multi-Etch solution etches faster than when it is first mixed up. But the difference takes months to notice.

Laboratory set-up to use Multi-Etch heateed

We also discovered that if you heat the whole solution just one time to 150–160°F, i.e., bring it to a boil and turn it off, that activates the solution and it will work much better at room temperature from then on. If you don’t have equipment to heat up Multi-Etch safely indoors, take a hot plate and a simple double boiler outside and heat it up there. Once it’s boiling or close to boiling, you’re finished! You can then use it while it’s still warm or let it cool down and use it unheated. But, it will always work faster if you can use it heated.

For help in creating a simple double boiler, see instructions here and watch our short video here

We'd love to hear your experiences. Leave comments and questions here.