Studio Mull

Mulling Studio Frames
Overview:
            How to mull together studio window frames. 
Definitions:
 
Procedure:

1. Find the paperwork for the mull you are going to work on. Make sure the invoice number on the frames and mull strips match the number on the paperwork.
2. Determine how the frames will be attached based on the picture on the paperwork.
   1. The nail fins need to be removed on the sides that are joined together.
3. Score the nail fin close to the frame. Snap off the fin with a mallet or by hand.
4. Drill the rebar 3” from each end and leave no space greater than 12” between holes.
   1. Alternate these holes between the 2^nd and 4^th channels in the rebar.
5. If one of the windows is being mulled on its sill, mark where the weep hole covers will be on the mull strip.
   1. Insert the mull strip into the mull strip router and notch out the weep hole covers.
6. Attach the mull strips to each side of the rebar by hand or using a mallet as necessary. Ensure it extends 1” from the end of the rebar on both sides.
7. Apply two strips of gasket tape between the area where the vinyl and rebar meet.
8. Apply a bead of silicone to the crevice on the top side of the vinyl mull strip.
9. Apply silicone on top of each of the ¼” holes drilled into the rebar.
10. Apply a bead of silicone to the 1^st and 5^th rebar channels.
    1. Apply enough silicone to fill the channels and create a 1/8” of crowning.
11. Apply epoxy mull glue to the center channel (channel 3) of the rebar.
    1. Fill the channel and create 1/8” of crowning.
12. Turn over the mull strip and rebar onto the frame. For an over/under mull configuration it will go on the bottom frame. For a side by side, it can go on either side using middle screws, attach the rebar to the frame through each hole drilled.
13. Repeat steps 7, 8, 10, and 11 to the other side of the mull rebar.
14. Pipe some mull glue onto a piece of scrap nail fin to perform your mull strip test.
15. Push the frames together where they are getting mulled. Make sure that the mull strips are on the outside of the frames. Clamp the frames together on both sides to make sure they fit snuggly together.
16. Allow to dry for 10 minutes.
17. Inject a small amount of silicone into the opening of the mull joint. Immediately after insert 3” piece of backer rod into the end of the mull joint.
18. Fill the remainder of the mull joint cavity with silicone.
19. Tool the silicone smooth and even with the frame.
20. With epoxy mull glue, apply a 6” drip cap piece, with an “DO NOT REMOVE” sticker on it, over the exterior portion of the mull joint.
    1. If the drip cap is on the sill or jamb, make sure to rip the fin off the drip cap before applying.
    2. If the drip cap is ripped and is bronze or black, touch the drip cap up with a permanent marker.
21. Apply the metal reinforcement brace or foam patch to the interior side of the window frame.
    1. The metal reinforcement brace is used on the jambs and head.
    2. The foam patch is used on the sill, to prevent the silicone from sticking to the wood.
22. Fasten 1X2” piece of wood to the windows nail fin, across the windows sill.
23. On combined units that are 95 ½” tall, fasten shipping boards to the nail fin spanning the mull joint.
    1. Make sure the board is long enough to provide sufficient support for the joint during the shipping process.
24. With alcohol and a rag, clean the window thoroughly.
25. Store the window, and its mull strip test, in the curing rack for two hours.
26. Move the barcodes all together to the same side of the window. Put your initials on one of the stickers.