How do you make a bulkhead?

[Safari Tim]

Today I started to do what I assumed would be a rather easy job. I intended to make a polyboard panel to cover up the original green plastic wall paper on my shower wall. The shower wall is also the side of the rear closet.

I took some brown paper stock that comes on those large rolls, and held it up to the closet wall and pushed it into the edges to trace out a pattern.

Copied that pattern onto the polyboard an wal-la.... terrible fit.

Tried it again with a new sheet of paper, and made a worse one.

Now I eventually got it to fit, but its not great. One side is trimed out with oak molding and looks fine. The edge along the wall, is well, yucky . I intend to caulk it, but it will then be yucky with caulk.

I'll attach a photo...

The real question is, how do you do this? How do you guys, and you know who you are, make those bulkhead walls that match the curve of the airstream perfectly?

I'll have to build a bulkhead wall for the fridge soon and my confidence is now shot .

Need some pointers please.

[overlander63]

Tim, if you've done all the normal stuff, and you just can't get the curvature right, take a piece of stock and set it where it's supposed to go, or at least in the position it needs to be.
If you have a compass (the kind with the pointy thingy in one end, and a pencil in the other), open it up and hold the pointy end against the curved part of the wall, and the pencil end on the stock board. Move the compass up the curved part of the wall to the top, and cut the board along the pencil line you just drew.
This is the "engineeringly challenged" method, no measuring, just draw and cut. Remember to hold the compas steady while drawing, don't twist the pencil end relative to the pointy end.

[scottanlily]

Hey Tim ,

I recognize that tub /shower arraingment ,although my tub still is that coral
pinky type whatever it is color.I did exactly what your doing using that pebbly white shower stuff from Home depot .You might want to use a long
piece of cardboard ,somthing that can hold the shape ,make the curved side (the new wall covering)
abit over sized slightly , then check fit ,file it down or use a wood
hand block sander and sand the curved edge top to bottom or lengthwise
a little at a time ,check the fit .thats what i did .you need to get your pattern pretty much right on .it takes some work to get it right .I was able
to get it done and fit good ,and Im no expert you can believe that.The paper
is just too flimsy to get a good pattern .I would use a piece of cardboard
or poster board type stuff that you rough out to the general shape ,then
start trimming the curved side first till your happy with it ,then go ahead and cut the straight side to fit (cardboard pattern).Now, all that Ive said may be worthless to try if
over63s method gets you there better and more importantly faster ,meaning
less trouble .

Scott

[Safari Tim]

OK, guys.

I guess it seems like I was on the right track. It's definately trial and error. Mostly error! lol

I guess, with Terry's method you'd have to do some rough cutting just to get the board close enough to run the compass on it.

I've actually done that before when I built my bench seats on the dinette for my '71. Didn't think about it for the bulkhead.

Just trying to think about the mechanics of it.

If you were trying to make a bulk head, you'd have to start with a rectangle as tall as the ceiling and as wide as the wall you want. But it wouldn't fit against he wall, so you'd have to start by triming the upper corner to get it close.

Next you run the compass against the wall marking the new bulkhead with the curve. Then you cut it out on your line.

But now, the bulkhead would be too short since you cut it down on your mark.

What am I missing here?

[LI Pets]

The trick I found with the compass it it needs to be at 90 degrees to the line you're following.

Try this, the paper needs to be secure tape it good into place, mark it up then transfer it to cardboard, find a furniture or refridge box to it's one piece.

Test fit if its short mark that spot how short and add a piece of cardboard in that area and recut.

If all that doesn't work (it should) take the old panel out and use it as a templet.

[GlenCoombe]

Tim, paper (compass method) top template, final material.... do the paper and compass method then transfer to a template. Use something you can "work" with a file, rasp or sissors. Then when you're happy with the template for the curve you can transfer to your final bulkhead material.
I can assure you the guys at AS work from patterns and all you need is a good one for most all your bulkhead needs. Trial and error for certain until you get the final pattern right. Then keep it for further use or loan to those in need with your year/model.

[Royce]

all of the above and for the final trim scribe you can use a steel cut washer. Select washer of correct size, edge of washer against scribe surface, pencil in hole of washer, follow scribe edge drawing a perfect line on the panel to be trimed.

[ALANSD]

if someone does this could they shoot a photo or two and show us dummies the steps. My templates in the past were always off a bit. especially the weird flooring angles around cabinets and such.

[thecatsandi]

Cardboard. Paper is too flexable. I use it for templates for airplane parts. Never misses. Cut it a little big and trim to fit. Takes a little longer but worth it in the end.

[overlander63]

Originally Posted by thecatsandi

Cardboard. Paper is too flexable. I use it for templates for airplane parts. Never misses. Cut it a little big and trim to fit. Takes a little longer but worth it in the end.

How about heavy cardstock? You know, the stuff that holds shirt collars up while they are in the store?

[Aerowood]

Go down to the arts and craft store and get several sheets of poster board, (the stuff that gift boxes are made of) tape a buncch together and then scribe the contour with a compass. I would be lost at work and at home without it. I make prototype aircraft parts with it all the time.

[markdoane]

I've been using sheets of Luan plywood. Best if you slap a coat of varnish on it to keep the splinters from jabbing you. I think it's just as cheap as posterboard and you don't need to tape it together.

[uwe]

Tim,

Either method described below is fine. The curve is where it's at.
Make sure the front edge and curve are squared ( that does not sound right, somehow)
Transfer to fiberboard or some other light but durable material for a template. Now you have a good starting point to make bulkhead panels.
In my case, I could not use the template without trimming subsequent bulkhead panels. The curvature in my interior is not identical everywhere.
So I always cut slightly too big on the curve, and then did fine tuning with the sanding block or belt sander, depending on the severity of the mismatch.

[Thealt]

I agree with all the above posts and there are many methods for making the pattern. Although I've not done it for this specific application, I do build furniture and have remodeled and built a few houses in my time.
Usually the issue here is that no 2 pieces are the same so making a pattern for each project is the only way to get a true fit. The common misconception is that a pattern must be a one-piece cut where the reality is that it just must fit the project and can have as many layers as lasagna.

On curved pieces or pieces with odd shapes, I typically use butcher paper or some other heavy paper to build up a pattern. To keep the pattern sticking to the project and to allow the paper's edge to be right against the outer most edge of the project, I cut slots along and about 1/2 inch inside the edge. Or I use a paper hole punch to perforate the paper along the edge so tape will lay over the holes, but still come in contact with the project behind. Imagine a sheet of 3-hole-punch paper. Duct tape is really good for sticking these on to the project surface. Alternatively, there are some spray-on temporary adhesives available at art stores to "POST IT" to the project then peel it off. Don't go crazy with the spray on. Just the edges and a couple of field dots to hold the middle of the pattern.

Here's what I typically do:
I cut a large piece of pattern paper to cover as much of the main part of the object starting with as many straight lines as possible. The floor and door jamb will be the straightest so I start with a piece of paper that will line up to one or both of those edges. From there, I move up the wall until I get to where the pattern doesn't cover. If I'm tracking up a straight line, but the paper is moving away from the project the higher up I go, I come back to this spot later and overlay another piece aligning the straight edge of the new piece of paper to the edge of the project. Tape is cheap and I like the blue temporary masking tape to be able to reposition pieces while building up the pattern, but I use regular masking tape to secure the pieces when it's finished.

Once I'm up to the curve, I cut pieces of paper into easy to manage sizes (4" x 6 or smaller), but this really depends on how much of a curve I am doing. With these pieces, I tape them to the large pattern piece and let them overlap the edge of the project about an 1". I work one piece at a time and only tape it to the main pattern in one location as I want to allow some play in the piece until I do the final cut. (Here's where a picture would do nicely, but think about it like using a post-it note to tage a page in a book. The post-it sticks only to one edge of the paper and sticks out beyond the edge so you can see it and grab it. Stick a ton of post-its so they over lap each other slightly to mimic the curve.)

Now with all the pieces overlapping the edge, I use a French curve (from any art supply store), or thin strip of wood to push the pattern pieces into the curve. This is where not securing them fully to the pattern allows them to move a bit when you start smushing them into corners. Once there, I use an Exacto knife to trim the pattern pieces to the curviture of the project. I cut a little and check the fit. I tape those pieces together close to the curve so they don't move. I continue this procedure along the curve. After the full curve is cut and checked for fit, I pull it off and put it back on to check my work.

After all that work your project should fit pretty darn close. Remember measure twice then have your friend measure twice. Then you measure again, cut once. Then if it doesn't fit... you can blame your friend.

Alt

[NorCal Bambi]

Tim, here is a method that a boatbuilder passed on to me when I was working on the Bambi. Trick is to hold the compass at the same angle while you are making your arch. If you look at my thread you will see pictures of the washer method. The boat builder add a post and gave me this method. It works great.
Don

[CanoeStream]

Long promised to many on how to duplicate any complex 2-dimensional shape: Story Stick to copy irregular shapes

Tim, I've promised putting the 'story stick' thread together to more people than I care to say. You are the motivation -- thank YOU (and Rob & Colin, et. al.) for all the hard work on The VAP.

[Safari Tim]

Wow, that's all I can say!

Thanks to everyone for the great tips. I'm sure I can tackle a bulkhead project now. I realize how difficuilt it is to explain techniques in writing.

Bob, thanks for the nice comments about theVAP! And the follow up with your 'story stick' method. I'm going to experiment with that one as well.

Thanks again everyone!

[Jim Clark]

Originally Posted by NorCal Bambi

Tim, here is a method that a boatbuilder passed on to me when I was working on the Bambi. Trick is to hold the compass at the same angle while you are making your arch. If you look at my thread you will see pictures of the washer method. The boat builder add a post and gave me this method. It works great.
Don

Norcal is righ, boat bulkheads are a harder to do, and a boat is never level. If you do a search for a tick stick it will also help to get the curve correct.

Here is a link to start you off.
Matching Curves With A Tick Stick

I have used this on several boat rebuilds and it works.

Good Luck Jim

[Safari Tim]

After all the suggestions presented here I opted for the Story Stick. I figured it would have the most chance of being success full for a rookie like me .

I ended up using a 5 gallon paint stick and trimed the end down to a point. I taped the paper on the bulkhead where I wanted my panel. You see a white panel there in the photo. That is the one I made that did not fit well enough for me.

Then I reproduced the story stick on my panel and cut it out. It fit much better. I could have made more story stick marks to reproduce it better, but the final product works good.

Thanks to everyone for the help! Here are some photos.

[FreshAir]

End of story.....stick. Good job. I spent 50 years building displays and tried most of these suggestions. All can work....it just takes patience.
Neil.