Poor Boy Steam Box Deglazing

Remove old panes & putty, cut & clean glass, putty & paint.
johnleeke
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Poor Boy Steam Box Deglazing

Postby johnleeke » Mon Jun 09, 2014 1:08 am

1148788_618756954836406_1334404555_n.jpg
Wood frame on foam board insulation, with sash inside. (click on image for closer view)

This is the "poor boy's sandwich steamer," that we use for ad-hoc onsite sash work. A foam board panel (partially in view at the right edge of the photo) is laid on top of the wood frame. The horizontal "sandwich" is made of two pieces 4'x4' foam board with the sash and a wood frame of 1x5 pine in between. Sash weights or bricks are set on top at each corner to hold the "sandwich" together during seaming.

Works lickity-split because of the limited interior volume, with temps at 205F to 210F.
Cold start steam time: 20 minutes.
Warm steam time: 10 to 12 minutes.
The short steam times seem to be related to the even flow of steam across both faces of the sash, and the relative small volume inside the box.With these short steam times a three-worker crew could deglaze 4 to 5 sash per hour, one worker keeping track of the steamer and handling sash and glass, with two workers scraping out putty and removing glass, cleaning out all glazing rabbets down to bright wood and 30 to 50% paint removal. This with an inexperienced crew just learning the steam deglazing method.
Takes less than an hour to build, see illustrations below for details.

These short steam times result in very little moisture in the wood. Before steaming the wood is 12-14% EMC. The outer 1/16" of wood after steaming is 18-22%, inner wood is still 12-14%. After 12 to 14 hours of drying at ambient shop conditions of 75F. and 60RH all wood is back down to 12-14%. A fan on the sash would speed up this drying.

Materials
--3 wood boards, 3/4" x 5 1/2" x 8', #2 pine
--20 wallboard screws, 1 5/8" or 2"
--1 sheet Thermax foam board insulation, 1" x 4' x 8', be sure to get Thermax or Tuff-R products (no substitutes), fiber-reinforced isocyanurate foam, coated on both sides with heavy aluminum foil.
--aluminum foil tape, 2" wide, for sealing edges of foam board
--4 window weights, or bricks to hold the corners down
--1 steamer, more on steamers here: http://historichomeworks.com/forum/view ... =2663#2663
--Optional: steamer hose adapted to 1 1/4" tapered standard (for details on this see the Steam Paint Removal Report http://www.historichomeworks.com/hhw/re ... .htm#Steam)

Thermax can be difficult to obtain. Sources: Call the maker, Dow Chemical Corp. for information about distributors near you: 1-866-583-2583 press 8 and talk to the representative who will pass your contact info along to a sales rep. If you are not a contractor or business, building construction product dealers usually carry or can order these products. If your local lumber yard does not carry it, ask them to call the number above, or go to dealers in the next larger town or city.

Tools
--tape measure
--utility knife
--pencil
--square
--cross cut saw
--table saw or rip saw for cutting baffle boards to width
--power screw gun with bit for screws
--1 1/4" spade bit, for steam nozzle hole
--3/16" twist bit, or 5/32", for screw shank holes

Assemble the box as shown in the illustrations below.

Operation
Lay one sheet of the insulation board on a flat bench or floor.
Lay the box on the board.
Lay down four little sticks of wood in each corner to space the sash up off the board.
Lay the sash in the box, exterior side up, on the sticks, slide an unpainted edge of the sash up against the baffle board, leaving a space between the other edges and the box.
Lay the other sheet of insulation on the top edges of the box.
Place weights on top to hold each corner down.
Plug the steam hose into the hole in the side of the box.
Turn on the steamer and begin steaming the sash.
After 20 minutes open up the box and check to see if the putty is soft.
If it is not soft, give it another 15 minutes of steam and check it again.
If it is soft, immediately remove the sash, lay it on the bench and begin scraping out the putty and removing the panes. You have just 5 to 10 minutes to get this done before the putty begins to cool and harden up. Use a pull type scraper to remove the front line of putty and glazing points. Use a crack tool to get out the putty between the edge of the pane and the neck of the glazing rabbet. When the pane is out, clean out the bedding putty with the scraper.
If you do not get all the glass out, let the sash dry out for a day, and then steam it again.

Richard Nisson came up with the idea of the "poor boy" when we were on a project in Nebraska. Works well when you have limited time or funds and one sash at a time makes sense. The next day I wanted to build them a bigger foam board box (ala Dave Bowers), but they said that's silly, let's just make another poor boy sandwich, it only takes 20 minutes.
Attachments
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Removing the pane after steaming and scraping out the old putty. (click on image for closer view)
1119976_618770361501732_2036756520_o.jpg
Sizing and making the wood frame. (click on image for closer view)
1176148_618777014834400_1066655814_n.jpg
Wood frame with baffle. (click on image for closer view)

johnleeke
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Re: Poor Boy Steam Box Deglazing

Postby johnleeke » Sat Feb 27, 2016 8:40 pm

If some paint remains after deglazing and partial paint removal there are two ways to proceed:

--You can set the sash aside to let it dry out for a day and then steam again. Be careful to not scrape bare wood that has been steamed or you will damage the surface of the wood by scruffing and threading.

--You can immediately use an infra-red heat lamp to remove the remaining paint. This dry heat will dry out any excess moisture in the wood and you can usually move ahead with with wood surface preparation, woodwork repairs and painting and glazing.

When in doubt if the wood of the sash is dry enough, use a moisture meter to measure the moisture content of the wood. The moisture content should be less than 15% E.M.C. to sand, use wood-epoxy repair methods, primer or paint.

Stacie
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Re: Poor Boy Steam Box Deglazing

Postby Stacie » Mon May 09, 2016 10:42 pm

Hi John,

Thanks so much for posting this! You noted 'no substitutes' on the rigid foam insulation, but I can't source either Thermax or Tuff-R locally. Do you know of other alternatives, or can you share what qualities these have that I can look for in another product? Also, when you say coated on both sides with HD aluminum foil, do you mean coated from the manufacturer (foil faced/back), or did you/could you apply the aluminum foil and secure with the aluminum tape?

Best!

johnleeke
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Re: Poor Boy Steam Box Deglazing

Postby johnleeke » Tue May 10, 2016 4:39 pm

Hi Stacie, welcome to the Forum.

The foam board insulation has the aluminum already attached to both sides. The aluminum is thicker that the typical consumer market aluminum foil for use in cooking.

1" thick ridged foam board insulation characteristics that make it work in this application:

-- provides thermal insulation that helps keep the heat inside the box
-- aluminum coating helps control the moisture of steam condensation
-- aluminum reflects heat back onto the sash's putty and paint
-- aluminum is thick so it is durable, but it is not as thick as aluminum sheet metal, which would absorb too much heat from the steam
-- it is a sheet material, so there are fewer joints for the steam to leak out of

Sources of supply:
Call the maker, Dow Chemical Corp. for information about distributors near you: 1-866-583-2583, and talk to the representative and ask for local sources or regional distributors, or she may pass your contact info along to a sales rep. who will call you back.
Building construction product dealers usually carry or can order these products. If your local lumber yard does not carry it, ask them to call the number above, or go to dealers in the next larger town or city. Let me know your location, and I'll see if I can help you find a supplier.

Alternatives:
Any foam board insulation may work, just not as well as the Thermax or Tuf-R.
Although I have never tried it myself, you could try simply using 3/8" or 1/2" thick plywood or 3/4" thick solid wood tongue and groove boards. The ply or boards will probably warp out of shape from the moisture. I would suggest painting both sides to make them water resistant, but the steam will probably loosen the paint. You might even be able to find aluminum-pigmented paint, but that is another specialty building product that may be difficult to source.

Other steam or infra-red lamp methods for deglazing sash may work well enough:
viewtopic.php?f=10&t=5199

Stacie
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Re: Poor Boy Steam Box Deglazing

Postby Stacie » Wed May 11, 2016 12:51 am

Thanks, John.

The double foil-faced insulation board does seem the best fit for this application. I will track down a building material supplier that is willing to order it in for me.

Thanks for the note on the aluminum sheet metal as well - I was considering that as an option for this project, as well as a shop steam box, and now understand why it is not being used.

johnleeke
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Re: Poor Boy Steam Box Deglazing

Postby johnleeke » Fri Aug 10, 2018 3:29 pm

The wood does get wet, but the moisture soaks into the wood only about 1/16" to 1/8" deep, and this is only where bare wood is exposed to the steam. Where there is paint and putty the moisture may not penetrate the wood at all, or at most 1/16". The shorter steaming times reduces how deep the moisture goes compare to a larger steam box that requires longer steam times. Deeper within the wood it is still dry. Right after the wood comes out of the box the heat from the steam begins to dry out the wood.
If the moisture measurement before is 15%, the 1/16" to 1/8" layer of wood may bump up to 18 or 20%, but after 4 to 12 hours it is back down to 15%. If you require a faster drying time you can blow a box fan on it. In practice, I often use an infrared heat lamp to do the final paint removal; so with that dry heat the wood is completely dried out within 5 to 10 minutes of infrared paint removal.
One issue is that a bare wood surface that has been steamed is soft and scraping may pull up "threads" of wood fibers. So, don't scrape where the wood is bare. Let the wood dry out, then the bare wood scrapes fine as usual.


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