Muntin Rib Repair (final)

Wood repairs for sashes, frames and sills.
johnleeke
Posts: 375
Joined: April 13th, 2011, 7:34 pm
Full Name: John Leeke
Location: Portland
Organization: Historic HomeWorks
Permissions: Yes
Location: Portland, Maine
Contact:

Muntin Rib Repair (final)

Postby johnleeke » November 18th, 2011, 5:19 pm

Muntin Rib Repair

Update: 8/22/12
Author: John Leeke
References: Save America’s Windows, page 51, 2009 (photos courtesy John Leeke)
Contributors: Amy McAuley, Peter Carroll, Bob Yapp
Title of Treatment: Muntin Rib Repair
Class of Treatment: [ ] Maintain, [ ] Stabilize, [X]Repair, [ ] Upgrade, [ ] Exception
Type of Treatment: [ ] Traditional, [X] Contemporary


Condition to be Treated: Split or broken muntin rib.

Description: These thin fragile strips between the glazing dadoes are easily damaged or weakened by decay. A rib that is split but still intact can sometimes be glued back in place. If the rib is decayed or missing, replace it with one sawn from wood. If a joint is made at the end of a rib repair, a butt joint can be used if epoxy adhesive is used; a scarf against water flow is critical if other adhesives are used. There are two ways to attach the rib to the muntin: Butt (with a flush butt joint, steel pins and adhesive; or Groove (with the rib set in a groove with adhesive). The groove may work better if the rib is less than 3/16” thick.

Typical Procedure:
1. If using a groove, scribe along the sides of the rib with a razor knife to the desired depth of the groove before removing damaged rib. This prevents tear along the shoulders of the groove and serve as a visual depth guide.
2. Trim away damaged rib flush with glazing rabbet shoulder.
3. If using a groove, carve the groove between the scribed lines with a narrow sharp chisel.
4. Make enough rib stock for all rib repairs. Match the thickness of the adjacent ribs.
5. Cut and fit the new rib.
6. If using a groove, glue rib in place and temporarily fasten twice or every 10" with tape wrapped around the rib and muntin. Allow adhesive to fully cure, then remove the tape.
7. If using a butt, use tiny stainless steel brads, pre-drill the rib with the brad, or spin them into place with a brad-spinner. Apply adhesive under the bottom edge of the rib, then set the brads 1/8" below the surface and fill with glazing putty. Allow adhesive to fully cure.
8. Trim the face of the rib flush with surrounding ribs or face of stile or rail. Clean any excess adhesive out of glazing rabbets.

Materials:
Wood, match wood of sash, very straight-grained
Adhesive, weather proof
Brads, stainless steel, if needed
Tape, blue painter's tape, if needed

Quality of Results:

Best Work: Rib matches originals in width and height. Face of rib is flush with face of surrounding sash parts. No adhesive buildup outside of joints. No adhesive at free joints. Rib is aligned square and true with surrounding parts.

Inadequate Work: Rib is tilted out of square. Gaps in the joints between the rib and neighboring parts. Rib is not the same thickness and width as original ribs.
Attachments
Rib1.jpg
Condition: split and missing rib.
Rib6.jpg
Step 5. Trim face of rib flush with surrounding rigs or face of stile or rail.
John
Standards Co-Founder
Standards Editor

http://www.HistoricHomeWorks.com

johnleeke
Posts: 375
Joined: April 13th, 2011, 7:34 pm
Full Name: John Leeke
Location: Portland
Organization: Historic HomeWorks
Permissions: Yes
Location: Portland, Maine
Contact:

Re: Muntin Rib Repair (draft)

Postby johnleeke » January 29th, 2012, 5:33 pm

What do you call the part that is being repaired here?


Muntin Rib (used in an 1890s trades manual and in many shops today.)

Muntin Fin (Bob Yapp)

Fillet (used by William McMillen during his demonstration at the 1997 Window Conference and Exposition in Washington DC; Steve Jordan says, "TECHNICALLY, IT'S A FILLET BUT I CALL IT A GLAZING BAR")

Putty bar (used in "THE PRESERVATION OF HISTORIC WINDOW SASH AND DOORS FROM THE PRESIDENT LINCOLN AND SOLDIERS' HOME NATIONAL MONUMENT, DRAFT TREATMENT PROTOCOL February 11, 2004)


Tongue (used today by Amy McAuley, and in England)

Neck

Flag

Bar (used in a few shops today, could be confused with the "muntin bar", which is a muntin that goes in one piece from rail to rail or stile to stile)

Slip

What word do you use for this part? Do you use a word not listed here?
John
Standards Co-Founder
Standards Editor

http://www.HistoricHomeWorks.com

oculus
Posts: 66
Joined: May 18th, 2011, 12:15 am

Re: Muntin Rib Repair (draft)

Postby oculus » January 31st, 2012, 3:57 pm

I first saw the term "tongue" used in the technical pamphlet The Repair of Wood Windows put out by SPAB in England. This publication must have come out over ten years ago. I have used the term ever since. This small pamphlet has been my bible for years now for intricate repair splices and sound conservation theory for window repair. Highly recommended!
Amy Harrington McAuley
Oculus Fine Carpentry, Inc.
http://oculuswindow.blogspot.com/
oculuswindow@gmail.com

"Opportunity is missed by most people because it is dressed in overalls and looks like work"-T.Edison

peter_carroll
Posts: 7
Joined: June 9th, 2011, 8:53 pm
Full Name: Peter Carroll
Location: Kalamazoo, MI
Organization: Old Home Rehab, Inc.
Permissions: Yes

Re: Muntin Rib Repair (draft)

Postby peter_carroll » March 8th, 2012, 1:39 pm

Probably the most frequent repair I make. Some "tongues" are not broken as much sculpted by weather or previous repairs. Can we make a recommendation when "tongues are sculpted by more than .........., recommend replacing them with new."

One small step maybe to add is to scribe along the sides of the "tongue" with a razor knife to the desired depth, before removing damaged piece. We found this prevents tear along the shoulder and serves as a good visual depth guide.

Joining "tongues" with good scarf against water flow maybe critical as the ends of new & original tongues are not epoxy sealed but glued.

johnleeke
Posts: 375
Joined: April 13th, 2011, 7:34 pm
Full Name: John Leeke
Location: Portland
Organization: Historic HomeWorks
Permissions: Yes
Location: Portland, Maine
Contact:

Re: Muntin Rib Repair (draft)

Postby johnleeke » March 8th, 2012, 5:13 pm

Peter writes:
>>Can we make a recommendation when "tongues are sculpted by more than .........., recommend replacing them with new."<<

Of course, by more that what? The way I made the decision is if the tongues are weathered so much they do not provide a good guide for the putty knife when glazing/

>>One small step maybe to add is to scribe...<<
Done! I've also added you as a contributor on this one.

>>Joining "tongues" with good scarf against water flow maybe critical [if] the ends of new & original tongues are not epoxy sealed but glued.<<

I use epoxy adhesive and plain butt joints with no failure that I've found. Scarfs are fun though they take a bit more time and skill, but I'm not against it. I'll add it as an alternative in the description.
John
Standards Co-Founder
Standards Editor

http://www.HistoricHomeWorks.com

Bob Yapp
Posts: 59
Joined: May 9th, 2011, 8:39 am

Re: Muntin Rib Repair (draft)

Postby Bob Yapp » August 22nd, 2012, 6:16 pm

I have always called these muntin fins. Not sure where I came up with this but have called them that for 39 years.

Bob Yapp
Posts: 59
Joined: May 9th, 2011, 8:39 am

Re: Muntin Rib Repair (draft)

Postby Bob Yapp » August 22nd, 2012, 6:26 pm

I'm not clear on this standard John. Are you saying to actually cut a groove/rabbet into the muntin after shaving the bad rib off? Or are you saying shave the rib off flush to the shoulder and then butt joint/glue the new fin flat to the muntin?

My method is to shave the bad rib flush and glue on a new rib with out a groove/rabbet. I use 2 or 3 tiny stainless steel brads, pre-drill the rib with the brad I'm using. I then set them 1/8"below the surface and fill with glazing putty. I use Tight Bond 3. I also scarf joint each new piece to solid old rib material.

johnleeke
Posts: 375
Joined: April 13th, 2011, 7:34 pm
Full Name: John Leeke
Location: Portland
Organization: Historic HomeWorks
Permissions: Yes
Location: Portland, Maine
Contact:

Re: Muntin Rib Repair (draft)

Postby johnleeke » August 22nd, 2012, 7:48 pm

Yes, actually cut a groove in the muntin.

During the 1970s and 80s I did it exactly as you describe with a flush trim, brads spun in place and epoxy adhesive.

Then I had a few window jobs with ribs less than 1/8", I used thick needles as pins, but the joints weren't strong enough. So I developed the groove method, and have used that ever since for thinner ribs. if the ribs are 1/4" I'd just do it flush with pins and adhesive.

Either way has worked for me. I've added butt with pins as an alternative.
John
Standards Co-Founder
Standards Editor

http://www.HistoricHomeWorks.com


Return to “Woodwork”

Who is online

Users browsing this forum: No registered users and 1 guest