Tips for Altering a Pattern... A lot??

[Sorcha]

Hi all!  Been awhile since I've posted.  Good to be back!  Anyway....

I'm working on a doublet pattern (McCalls 4695).  I have used this pattern in the past and only needed to alter it slightly by drafting out the darts.  It worked out well and fit nicely.
Now I'm using for a friend's piece.  The challenge is the man is VERY big.  Not just around, but long too.   I'm using the largest size pattern offered (46), but I'll still have to lengthen it almost a half foot!   
I'm not overly concerned about lengthening it because the pattern is clearly marked with locations for that, it's trying to get the additional width right.  It's sized as a 46 chest measurement and the man measures 49.5 
I'm also concerned that I'll have to alter the pattern so much it will start to get all wonky.
I know a muslin is always an option, but I need a place to start.

So who's got tips?? 

[mellingera]

First, when you made the first one did you notice if it ran a little large? Lots of times with commercial patters they run larger than the measurement they specify, sometimes by inches! At least in my experience...

Second, I have had to widen tops for myself in the past, sometimes the shirt I like doesn't go up past 42" bust (problem when in your best bra you are a 46.5!) Here is what I have done (Hope you like MATH and Fractions ):
Step 1: find the difference in the measurements to determine how much you need to add, in your case you are looking for 3.5"
Step 2: determine how best to spread it out evenly so as not to distort the pattern. I have never used the pattern in question, so I don't know how many seams there are already. For the sake of my example I am going pretend the pattern has 4 pieces (2 side back pieces and 2 side front pieces) Plan to widen each of the individual pieces of the pattern on each side. So 4 pattern pieces x 2 sides = 8 places. Divide 3.5 by 8 and you need to add 7/16" to each edge. If that still seems to you like it would turn out wonky, you can split each pattern piece down the middle and divide by 12 instead, spread the middle of each piece by 7/24" and add the same on each side.

[CountessofPhoenix]

Be careful enlarging the shoulder crosswisw. My husband wears a 5x but he has 3x shoulders. Some larger fellows are really pear shape, and they don't need the extra across the shoulders. To go up 1 size you can usually add 5/8 inch around each seam allowance. Don't forget if you enlarge the seams around the arma and neck to adjust the curve too.

[DonaCatalina]

If you have some cheap giftwrap with a white back, you can re-draft a commercial pattern by copying the pieces onto the wrapping paper and then enlarging according to your measurements. Then you can get the proper slope between the waist and the shoulders so that it fits.

Then you can test your enlarged pattern on some cheap muslin.

[LadyStitch]

I tried to up size a man's shirt and I found that just because I made the pattern bigger didn't mean that the fit was right.  I found that the bigger the guy the more the neckline changed.  Make a mock up with muslin before you cut from the main fabric. Trust me I found out the hard way and spent an hour crying and 8 hours rebuilding.

I agree that most big guys are pear shaped. My friend Russ I ususally buy a 3X pattern and "pivot" the sides out to allow for his girth.

For visual references I'd say check out "Singer Basic Sewing" or  "Readers Digest Guide to Sewing".   Those are the two "text" books I send people to when asking for visual suggestions. 

Hope that helps

[Kate XXXXXX]

DO NOT add extra at the side seams and /or CB abd CF and expect it to fit!  It's better to cut the pattern piece up the middle and add the extra there if the customer needs extra all the way up...  If he doesn't need it wider on the shoulder, cut up to the SEAM LINE and pivot...  BUT do the length at the same time!  You'll end up with some added to the length at the CF, some added to the width all round, and may not need to add to the length at the CB or sides, if you are accommodating a 'bow-window' figure with a lot of tum but not a lot of extra height...  You may in an extreme case find that you need to add ALL the extra to the front.  If you need to add it all the way round, divide the amount needed in four, and add  this amount to the back and front pattern pieces.    If you need to add it just to the front, try doing it in two sections, rather than all in the same place!  I find that adding half at the centre shoulder and half at the top of the curve of the armscye works well.  Once you get this right, you can enlarge the neckline where needed if there is a large neck to accommodate.

These pictures will give you an idea of the sort of additions you may need to make to the pattern: http://www.diceyhome.free-online.co.uk/KatePages/Costuming/Dickens/satinlayout.JPG
http://www.diceyhome.free-online.co.uk/KatePages/Costuming/Dickens/bothfronts.JPG
You can see where I added to the front length and the width to accommodate the larger figure, but did NOT add to the length at the side seam or back seam/opening.

While primarily aimed at women, these books will help enormously with general fitting issues:

Fitting Solutions: Pattern Altering Tips for Garments That Fit by "Threads" Magazine (Paperback - 2 May 1996)

Fast Fit: Easy Pattern Alterations for Every Figure  by Sandra Betzina (Paperback - 3 Jun 2004)

The Perfect Fit: A Practical Guide to Adjusting Sewing Patterms for a Professional Finish by Creative Publ Intl (Paperback - 28 Oct 2005)

[gem]

I tend to have better luck draping and tweaking than I do with altering existing patterns.

If you're like me, you might find this tutorial on drafting a doublet pattern from an existing shirt helpful.

I've also found that comparing a garment's measurements with an existing garment of the approximate right size can be very helpful.  Of course, a T-shirt doesn't fit anything like a doublet, but you can use it to gauge approximate scale, at least--does the neckline seem like the right size; am I in the same realm with this back width, etc.  It's one more visual cue that can help keep you on track.

Good luck!

[Sorcha]

Okay.  Color me confused.
I know these are all good ideas.  Some work for some situations, some for others...

Perhaps if I add more information:
There are only 3 pattern pieces for the body. (1 Back/2 Fronts)
My giant firend isn't very pear shaped.  A few extra pints at the pub, but not much.  The neck to waist measurement I took originally was from the back.  And according to the pattern, I will need to add true length, not just yardage over the "bow-window".
His other measurements are:
49.5 Chest
47 Waist (The widest part)
18.5 Neck
I do like the idea of redrawing on the back of wrapping paper.  I'll still use the preprinted markings for the lengthening, and the site that uses an old shirt for a pattern is really helpful for fitting.  I am a visual person, so the pictures are GREAT!
But to cut up the middle or add to the side for width?  Sounds like for this instance, the middle of all three??  I think he's proportionate enough to add evenly around...  Or am I missing something else to consider other than the bow-window/proportion issue?

[LadyStitch]

Well try a toil/mockup of you adding it all at the sides and try it on him. See where the wrinkles are and where he needs more room.  He sounds like he is built like my Rugby player friend.  Big, broad, and tall.  When i made his pirate coat I added to the seams to make it bigger, but when I put it on him I found that I needed to do a slight adjust for his 19 inch neck, a slight slope for his girth, and lengthing the arm hole a little since he had big shoulders.

You have been getting great advise from everyone.  Only thing I can say is try a toil/mockup of something on him and see where you can make a change.  That would at least get you a step toward what you need. Sewing for big guys is never easy but it is appreciated.