Hi,
Only FWIW, I've used MEK for limited, specific purposes for decades.
For our purposes, MEK requires similar care to that required for Toulol,
and pretty much anything that provides similar functions.
Like everything else that we use as tools, we have to educate ourselves
about our tools; especially ones that are chemically active. For me,
this includes looking up the MSDS sheets from time to time to see if
anything has changed since the last time I looked. Many times, it's all
the same. Sometimes, it isn't. In any event, what's important is to be
reasonable and careful in our use of substances for which there aren't
necessarily any equally efficient and effective ways in which to do our
work.
I agree, Peter...time to start experimenting.
Kind regards.
Horace
On 2/13/2019 7:24 PM, Peter Grey via Piano Technicians Guild wrote:
> Please do not forward this message due to Auto Login.
>
> This is great information.
>
> I used to think that MEK was carcinogenic, but evidently it is not. Causes brain damage if exposure is too high but it won't give you cancer. Thats good. I also have a can of it and never knew what to do with it. Time to start experimenting...
>
> Thx Glen.
>
> Pwg
>
> ------------------------------
> Peter Grey
> Stratham NH
> 603-686-2395
>
pianodoctor57@gmail.com> ------------------------------
> -------------------------------------------
> Original Message:
> Sent: 02-13-2019 21:04
> From: Glen Hart
> Subject: Paraloid B72 as hammer hardner
>
> Thanks for making that clear. That's what I was trying to convey when I wrote: " isopropyl is not necessarily rubbing alcohol". Any "relatively anhydrous" alcohol works well. Usually rubbing alcohol has some oil and sometimes fragrance in it and lots of water. The only reason I seldom use it is because MEK is so much faster in showing results. Most of my work is in the shop so the smell is not a problem.
>
> ------------------------------
> Glen Hart
> Grand Junction CO
> 970-434-5558
> ------------------------------
>
> Original Message:
> Sent: 02-13-2019 15:13
> From: Ed Sutton
> Subject: Paraloid B72 as hammer hardner
>
> Glen-
> Interesting information.
> I suggest one refinement: although 70% isopropyl alcohol is the most common dilution, it can be found in drug stores in 99% and 50% dilutions as well.
> The 99% isopropyl seems to work quite well with paraloid B-72.
> I have found isopropyl the least offensive smelling solvent and especially prefer it for use in homes.
>
> ------------------------------
> Ed Sutton
>
ed440@me.com <
ed440@me.com>
> (980) 254-7413
>
> Original Message:
> Sent: 02-12-2019 23:05
> From: Glen Hart
> Subject: Paraloid B72 as hammer hardner
>
> Hello All- I'm late to the party as usual. Unfortunately, my reading habits are such that I don't read this blog regularly. My experiences with acrylic resin may be useful to some of you. I was first introduced to Paraloid B72 (then called Acryloid) in 1978 in a paleontology class. We used it for consolidating fossils by applying it with paint brushes. B72 was purchased in pre-mixed liquid resin form. There was also a powdered version that dissolved quickly. However, I don't think it was B72 resin. There are dozens of Paraloid resins with varying properties. There's also a line of "A" resins. Much info on B72 can be gleaned from paleontology and museum conservation web sites. I never thought much about Paraloid resins until 1989 when I was re-introduced to it while learning gold leafing in New York City in the Metropolitan Museum of Art. It is used in the art world to consolidate decomposing gesso (among countless other uses). I restored a 1903 gold leafed Steinway B
> that was on the cover of the PTJ in 2001. The piano had a few areas of gesso under the gold that were strengthened with B72.
>
> Up until the 1990's I used nitrocellulose (NC) lacquer and occasionally shellac for voicing hammers. I once spent a day learning "lacquer voicing secrets" from Raymond Parada, one on one, in his office in the Steinway factory. He was "The Man" for a long time. They weren't really secrets, just the tried and true methods. NC lacquer voicing is a perfectly legit method of voicing so don't believe all the bad press. Also, the definition of a quality hammer is not based on the presence or absence of hardeners.
>
> In the early 90's I began experimenting with B72 for voicing but had a limited supply. This was before the days of the internet. Because of price, availability, the preparation hassle and inconvenience of Paraloid B72, I just quit using it when it ran out. It's great that it is now readily available to us. The results were excellent and I preferred it over NC lacquer. I had a limited amount of experience using it for voicing. Probably only 4 or 5 sets of hammers. There are lots of sources for acrylic resin. I have a dedicated spray room in my shop and have always used Sherwin-Williams products for refinishing, mainly because of availability. I found that their "Moisture Resistant Lacquer" was a good source for a Paraloid B?? acrylic resin for voicing. The problem with lacquers has always been in knowing the "percent solids". This is eliminated with B72 as it is 100%.
>
> The entire purpose of all this rambling is to present a new protocol for juicing up hammers. For at least twenty years I have been using two types of resin for voicing and have proven them over and over. I've never heard of this before but I'm sure that somebody, somewhere has to have had the same idea. There are a lot of smart technicians in the PTG with thousands of years of experience.
>
> The first is an acrylic syrup. I dissolve it in MEK or acetone. In MEK it's ready to go in less than 5 minutes and in acetone about 10-15 minutes. It is used just like Paraloid B72 or acrylic or NC lacquer, or keytop or hammer hardener from supply houses. It also cheap and readily available. This is just acrylic cement; aka: good ol' sniffin glue. Don't worry, it's no more dangerous than any of the other voicing solutions. It can be purchased locally and has a long shelf life. It can be mixed by weight or volume. For every gram of resin I'll mix 5-10-15 or whatever grams of solvent, or drops or eyedroppers or tablespoons. I've never been too worried about exact ratios. I just think of the solutions as weak, medium, or strong. This isn't rocket surgery. It is always amusing when people agonize over whether to use a 1:8 or a 1:9 solution. The type of alcohol is not important. Methyl is the hottest, then ethyl, then propyl. A can of hardware store denatured alcohol is all
> you need in the shop. It is mostly ethanol, denatured with methanol. If you need something hotter, such as for French polishing shellac, then you can buy straight methanol. Otherwise, a few seconds difference in flash time isn't going to matter. (The flat areas of the gold piano were French polished with methanol.) Just stay away from rubbing alcohol as it contains 30% water. BTW- isopropyl alcohol is not necessarily rubbing alcohol. Water will affect the resin and you definitely don't want to be pouring water onto felt that you're trying to harden. Water doesn't dilute alcohol; alcohol dilutes water.
>
> The brand of acrylic glue I buy is Weld-On #16 for Acrylic Sheet. I'm sure there are other brands that will work just as well. Acrylic syrups vary from approximately 70% to 90% resin, so get the the good stuff. From my observations over the years it seems to be slightly harder than B72. I have no data or done any testing so I'm just throwing this out there for whatever it's worth. Also, I've never used the granules from the supply houses and the last time I used keytop was thirty years ago. BTW, we occasionally hear of "collodion" used as a voicing solution in Europe. I've never used it. (What is sold today as a cosmetic is not the same stuff.) It has developed a sort of romantic aura about it, possibly because it is banned in the U.S. or that we imagine that it would give us that perfect elusive, magical tone if we could only get our hands on it. It is nothing more than nitrocellulose resin dissolved in ether and alcohol. It's probably one of the more dangerous concoctions
> in the shop.
>
> The second voicing resin is my favorite and I use it almost exclusively. It is pure vinyl resin -PVC. This is sold as clear PVC cement that is used for connecting white PVC rigid pipe for plumbing and irrigation. It uses MEK as a solvent which stinks to high heaven. It can be thinned with acetone or alcohol for less smell. It also comes in a low VOC version which I have not tried. It is great for the wholesale soaking of new sets of hammers and it has saved my bacon more than once on hammers that aren't supposed to have hardener but needed something more in certain areas such as the killer octave. This resin builds up the shoulders, i.e., power, quickly and the noise is easily voiced out with crown needling (with the Hart Voicing Tool of course!). If a little more "bite" is needed, the tone will come right back up with a light sanding. The beauty of these two resins is not in the tone or power they create, it's in the convenience and preparation time - a matter of minutes.
>
> All of these resins have a drying time and a curing time. It can take months for the resin to give up the last little bit of solvent before we know the final tone. MEK is the fastest. Alcohol will take the longest to give the final result. Lacquer thinner is probably the most practical since MEK is not available in some states.
> I have found that in new hammer installations the PVC in MEK is the quickest and most stable. It will be interesting to see if this catches on or fizzles out. Hopefully this information is of some use. If so, remember you heard it here first. If not, I'll be the guy walking around the conventions with a bag on his head! Happy Voicing - Glen
>
> ------------------------------
> Glen Hart
> Grand Junction CO
> 970-434-5558
>
> Original Message:
> Sent: 01-31-2019 18:07
> From: Peter Grey
> Subject: Paraloid B72 as hammer hardner
>
> Since alcohol is hygroscopic, I wonder if the addition of water to the mix helps mitigate the hardening action slightly.
>
> Pwg
>
> ------------------------------
> Peter Grey
> Stratham NH
> 603-686-2395
>
pianodoctor57@gmail.com <
pianodoctor57@gmail.com>
>
> Original Message:
> Sent: 01-31-2019 11:25
> From: John Musselwhite
> Subject: Paraloid B72 as hammer hardner
>
> I bought mine from a Canadian conservation supplier as it seems Dale doesn't ship it to Canada (as I recall). I used the instructions here <http://www.bentsidearts.com/upcoming%20Projects/?fbclid=IwAR3RuwQZ_uTHfIFAiX9LezgUZQjyQB8GkeZhO0PBFP_3U8_CyK1flN0Anm0>: (click to see the site from Bentside Arts)
>
> Rather than using acetone I prefer a "rectified spirit" like Everclear and use a transfer pipette to apply it as per the instructions. So far I've been quite pleased with the results.
>
> I made up full-strength and half-strength and keep it in the tiny plastic liquor bottles like you get on airplanes. I carry Protek and Profelt in similar bottles but have a different shaped bottle for each liquid. All bottles are labelled with a Brother Label Maker so I know what's actually in them!
>
>
>
> ------------------------------
> John Musselwhite, RPT
> Calgary, AB Canada
>
www.musselwhite.com <http://www.musselwhite.com>
>
> Original Message:
> Sent: 01-30-2019 17:45
> From: Dave Conte
> Subject: Paraloid B72 as hammer hardner
>
> I have purchased and want to try using Paraloid B72 as a hammer hardener.
> The package says 95% acetone mixture for consolidating or reinforcing
> plaster like materials.
>
> What does anyone using this for hammers use as a proportion for hammer
> hardener?
>
> ------------------------------
> Dave Conte
> Owner
> North Richland Hills TX
> 817-581-7321
> ------------------------------
>
>
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Original Message------
This is great information.
I used to think that MEK was carcinogenic, but evidently it is not. Causes brain damage if exposure is too high but it won't give you cancer. Thats good. I also have a can of it and never knew what to do with it. Time to start experimenting...
Thx Glen.
Pwg
------------------------------
Peter Grey
Stratham NH
603-686-2395
pianodoctor57@gmail.com
------------------------------