DPM vs TPM odor/smell

Just curious for those who have tried both DPM and TPM. Do they smell equally the same? I’ve been using DPM for a couple of months now and although it smells different than IPA, it’s still not pleasant.

@DKirch maybe you can comment since I know you’ve looked at both internally?

Having used IPA, TPM and DPM its fair to say that DPM is the least offensive of all the smells. Its a slightly musty smell, but not very offensive. TPM is more like ether, and IPA we are all familiar with!!

Oh great question. Happy to ask around the office a bit to see what folks think.

Interesting, thanks @Dxxxx! I guess the smell of DPM just doesn’t jive with me. I mean…I think it’s better than IPA, but it definitely still smells.

I can’t relate to what ether smells like but I’ll take your word that DPM is the least offensive.

Hello,
rezing the necro thread because it’s become important to my makerspace to have an answer on this.

hey @UALibTech ,

I believe @Dxxxx has about as good of an answer from user experience as you can get at this time; personally I have not used DPM but can agree that TPM smells like ether or antifreeze (kind of a sickly sweet smell) and IPA has a bitter alcohol smell. Hopefully someone else with DPM experience can chime in for you as well to affirm Dxxxx’s experience with it.

Well, by way of an update - two years on and a LOT of printing done. Looking at our old records a similar amount of printing (based on resin used by weight) would have used over 200L of IPA in our clean up (when we used just IPA)

We have used just 41L of DPM and 2L of IPA (Final quick rinse off)

There is NO WAY we would ever go back to IPA or TPM again (too smelly / expensive)

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The smell of DPM is very pleasant to me(slightly sweet). It works really well and saves a lot of IPA, but it kills your form wash.

We totally agree with the comments of Fantasy2. - but qualify the comment “it kills your form wash” IT DOES NOT STOP THE FUNCTIONALITY of the Form wash - instead it strips off the powder coating; Which just demonstrates to us how effective a solvent DPM is compared to TPM or IPA.

The reality is that the powder coated parts in the Form Wash are powder coated using the cheaper method of powder coating WITH THERMOPLASTIC MATERIAL.

An alternative technique for powder coating is the use of thermosetting powders which are more expensive to do, but significantly better at chemical resistance.

For steel parts exposed to DPM (a very powerful solvent) we found that finishing by E-Cote to be the best possible (and cheaper than powder coating in thermoplastic materials and significantly cheaper than finishing by powder coating using the better (for chemical resistance) thermoset powder coating)

Some interesting articles:

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Hearing all this is pretty interesting. We used DPM for a short while and found that the oiliness and length of time it took to evaporate was undesirable. We were having to dunk parts washed in DPM into IPA afterwards to remove the oiliness. Because we didn’t want to have to purchase/store two types of solvent, we went back to IPA and just bought a small distiller from Uniram to save on waste/disposal/cost. It’s been working great for us so far!

Leonhart88 - interesting points about “oiliness and length of time to evaporate” both of which are completely correct, but are linked in our view to one of the benefits of DPM - it does not readily evaporate, which in turn helps stop the loss of the solvent to the workshop atmosphere. We found we could lose up to 15% of the IPA in a Formwash in a week. Which in our view created a risk (and smell) in the workshop. The risk was mainly the fire risk from the evaporated IPA fumes.

We did try for a while simply washing the part in water - DPM is completely soluble in water but water takes a lot longer to dry than a quick dunk in IPA to clean off any residual DPM, so for our own needs (which included speed of process) we use IPA to clean off any residual DPM. Remembering of course that the IPA is not being contaminated by uncured resin, its simply removing any residual DPM which means it lasts a very long time.

Keeping the IPA tank sealed between uses helps keep evaporation to a minimum.