MPF Conservation conserved and/or restored two dozen pieces of Mason Monterey furniture from the Chateau at the Oregon Caves National Monument (NPS); MPFC was tasked with conserving two, the Blue Geometric (far left) and the Floral (far right) for the Museum Collection, shown above after treatment. Rather than choosing one to feature, because they had different issues, we are combining the post into this one on both, and will indicate which we are working on throughout. This is page two; to begin at the beginning, go back and start here.

Our thoughts on how Mason created his seating: We believe his unfinished leather seat was applied with uncolored lacing, and the entire seat was then colored using an oil-based glaze while in place. This accounts for some unusual things we encountered, including a lighter stripe on the groove where the lacing lay.

Further, there were two types of leather lacing on the seats: What we believed was original, and then a second generation which was used in specific places but never over an entire chair, samples shown left above. Our new lacing is shown untreated on the left. We “painted” an entire roll of new leather lacing using a glaze created for the Mason Monterey furniture, shown right, and hung it to dry for two weeks.

Leather: Cleaning

Both seats have their original historic leather intact. The leather was strong enough for cleaning.

Lacing was removed from both chairs at this time, but the leather seats were left sitting in place on the chairs.

We cleaned the seats using de-ionized water with cotton swabs and soft diaper cloth. Under both seats was an accumulation of years of debris, and this area was gently lifted and cleaned, shown right.

We were unsuccessful at removing most small white paint drops presumably deposited on the historic surfaces during painting of the walls in the Chateau, not with dental picks nor our fingernails!

Leather: Consolidation

The leather on both chairs had a good deal of red rot.

Two coats of 2% Klucel G in Isopropyl Alcohol was used to treat red rot, on both the top of the clean leather (above) and the underside. While it won’t reverse the effects (damage) already inflicted, it will stop the rot from spreading further. It is likely the original leather acquired red rot because Mason painted the top of his leather, and did not treat the underside. Further, all items with red rot are to be stored separate from other items with applied leather in the Museum Collection, so other items are not infected with the fungus.

Leather: Repair

The entire front edge of the Geometric chair was ripped through, shown left during the first assessment in the Chateau storage.

One option was to replace the leather, but as this was headed to the Museum Collection and not to be sat upon, we chose to repair the historic seat.

Our method was simple but effective. We clamped the seat flat against the table and weighted the seat in place. White glue was used as it is a surface repair, not structural, and would also not seep through the leather. Fabric bandages were created, placed across the rip, and held in place for 24 hours until cured.

The seat had to be handled carefully during the process. We gently lifted it and turned it over to infill the white bandages where there were gaps in the leather, above.

We turned the leather once more and set it onto the table. We set the chair on top while re-attaching it to the frame.

Fresh, longer tacks went back into the original holes, above, and were gently tapped into place.

Right, the seat attached again before lacing.

Leather: Lacing

We gathered all the continuous original historic lacing and placed it on the Floral Chair, shown above, along the back. There was little historic lacing.

Samples of the original lacing were returned to the NPS in the treatment report.

Once the lacing cured, new lacing was utilized along the other sides, shown left. Extra lacing was placed under the seat to redo the back if the historic lacing failed.

New lacing was placed on the Geometric chair, and we replicated the knot patterns on both as best we could.

Before and After!

Above, a slideshow of the Mason Monterey Geometric Horseshoe-back chair
after treatment. Below, before treatment (left) and after treatment (right).

Below, the Mason Monterey Floral Chair
before treatment (left) and after treatment (right)