New England’s Champion Hemlock Project – Treated with Pentacryl

By Ray Asselin (Preservation Solutions customer)

This New England champion hemlock tree, which grew on historic Mt. Tom (Holyoke, MA), was toppled in December 2013 by a windstorm. There is no other known hemlock in New England that comes close to this tree in size. The tree was approximately 250 years old, and our group is in the process of cutting a few discs from the log.


One of the discs will be a historical time-line display, showing historical events pinned to its annual rings, to be displayed for the public in the Mt. Tom Visitor’s Center.  Mt. Tom is also home to the state’s champion Red Pine and Black Birch.

March 20, 2014

We’ve cut several discs from the hemlock log, which is about 46″ in diameter. There is some rot in the center of the log, but we have at least one disc that will be suitable for the display. Based on the Wood Calculator, it will require 2 gallons + 3 quarts. I have written a blog article describing our first outing to harvest a disc recently.

March 26, 2014

We won’t be able to bring the discs indoors as we don’t have any appropriate place. They’re stored covered in an open-sided shed, which is where we’ll be treating the selected one. Hopefully it’ll be thawed by the time the Pentacryl arrives, or shortly after. At this point, we had expected to follow the guidelines on your website, i.e., put the disc on a sheet of plastic, brush on liberal applications of Pentacryl, as many times as necessary to get full penetration, then seal with End Grain Sealer, and store on edge.

April 1, 2014

We’re going up to Mt Tom tomorrow (Weds) morning to work on the disc. We want to apply the Pentacryl then. Attached is a photo of the disc that I think will be the keeper.


June 19, 2014

Not too much to report at the moment; the cookie is drying, and the last time I saw it, about a week ago, it looked good. The other, untreated cookies we have are beginning to check, but the treated one looked ok. We did put the Polycryl on the soft, punk area, but there wasn’t enough to really do the job, so I’m not sure how we’ll handle that. The center has a substantial amount of rot that, now that it’s thawed out and drying, is essentially dust. It wouldn’t take much to cause the entire center to fall out, but there’s enough of a web of un-rotted wood in there that we don’t want to lose it (although it could easily separate from the surrounding good wood, leaving a donut hole). Attached are a few of the last pictures I took, which was back in April, 2014 as we were applying the Pentacryl. I’ll take more when the project is completed.



July 11, 2014

We checked on the hemlock cookie today. Looks good, no cracking… I attached a photo of it, and one of another cookie that was not treated; that one is cracked.



August 15, 2014

So far, the Pentacryl seems to be doing an excellent job, no cracking at all yet. We took the cookie to a local bandsaw mill, where they sliced a bit off the top and bottom of the cookie to render a better surface than the original chainsaw cuts, and to make the thickness consistent. The other day we did a first sanding of the “show” face, to see how it would look.


This picture shows the cookie at the sawmill, after slicing off the top; the center rot doesn’t look too bad here, mainly because the saw filled voids with dust.


I’m sanding the cookie. We brushed the resultant dust into the rotted center area, and have applied diluted white glue to that area to hopefully solidify/harden it.


One of the other untreated cookies, which has a large crack.

Preservation Solutions Comment:

Hi Ray-

Thank you for the pictures!  This is a pretty piece of wood!  I showed the pictures to Dale and we are both pleased with the results.  Dale did mention to continue to dry the piece slowly and then once completely dry to apply a sealer to protect the wood.

The glue in the middle should dry OK.  Send a picture when this piece is on display.  Thank you!

October 10, 2014

The New England Champion Hemlock cookie is now a success story! Today Bill Finn, Don Rickson, Tom Quinn, and I brought the completed disc to the Mt. Tom Visitors Center, its home base.  That’s where it will be on display.  Bob Carr and Matt Villamaino of the state Department of Conservation and Recreation (DCR) at Mt. Tom will prepare a stand to hold the cookie upright; at the moment, it’s lying flat on a table.

We’ve filled the rotted center section, then sanded both sides of the cookie, and applied 6 coats of varnish to each side. Although I’m sure the wood is not thoroughly dried out yet, the surfaces were dry enough to varnish it, which should help keep the drying rate slow. Only small hairline cracks have appeared on the faces, nothing of concern.

Attached are a few photos taken in the Visitors Center today.


Cookie at visitor center, (left to right) Matt Villamaino (DCR interpretive staff); Don Rickson, Tom Quinn, Bill Finn (all of Mt Tom Advocacy Group), and of course, “Cookie”.


I replace Don Rickson.


Photo of the outside of the Visitors Center, a historic stone building in the Mt Tom State Reservation.

So, that’s the end of this story for now. We’d like to thank you once again for your generous help in making the project a success. We’re excited about how well the cookie turned out, and know that a lot of people will enjoy the display for many years to come. I’ve enthusiastically spread the word about Pentacryl to a number of people, and will continue to do so.