Following the steps in part 1,  the results at this stage should be,
well… an ugly mess.      Don’t fret.   This is where the fun begins…

Generally speaking,  I like to prime right over the raw, untouched
bondo and gap sealer before I sand.  Personal preference I guess.

If you want to do some additional Bondo work, glazing putty and sanding,
before primer, go right ahead.  It’s YOUR helmet.  

Here is the helmet after a coat of primer. Yes, I primed over the visor,
as it’s junk anyways and will be replaced with a MUCH darker material in part 3.

Here’s the helmet after some initial sanding.
Why I prefer to prime over the raw Bondo is to help see the “contrast”
between the primer, Bondo and undersurface.

Obviously, the white spots are low spots, whereas the primer is “middle”
and the pink is the bondo high spots.

For those new to surface prep, you want to sand down the high areas without
digging too much into the lower areas.

Since you are using anything from 40 to 100 grit to sand down the bondo,
it’s easy to tear into the plastic and mess things up quickly.
If you do gouge a chunk of plastic out, it’s not a huge problem.
You can mix up some Bondo, or if it’s a really bad chunk,
mix some plastic shavings in with some plastic weld and apply to the spot.

When you are done sanding, you should see smooth transitions from your surface
to the bondo. It’s okay to run your hand over the surface a few times.
Since you used a very rough grit to knock down the primer, you’ll want to
move up a few stages and get the heavy scratches out.
If you started with 40-60 grit, move up to 100/120, then 180/220, then 320.
If you started with 100/120, move up to 180/220, then 320.

If you want, you could sand with 400, but you’ll be wet-sanding with 400 soon anyways.

As you sand, you may want to, from time to time,
clean the surface with a tack rag and apply a fresh coat of primer.
Be careful not to apply too many coats of primer.
Wait about an hour after applying primer before sanding, no matter what the can says.

At this stage, between sandings you really only want to be applying a light
“dust coat”, otherwise you’ll develop problems later on from too many coats of primer.
After a few coats of primer, you may want to wet-sand the primer with 400 grit
sandpaper, and then wet-sand with 600 grit in order to start
smoothing things out for the color coat.
Personal Preference, as some wait to wet-sand after the first coat of the color.

In part 3 we’ll do final surface prep, color coat and weathering.

One of the most essential items in the prop-building arsenal is a Vacuum-Form Table.
There are many plans, howto’s and blogs on the internet showing the
general overview of constuction, but “step-by-step” instuctions can be hard to find.

This table is based loosely on information from TK-560,
however this guide fills in the gaps in an easy to follow, step-by step guide.

Let’s start with the “work” table itself.  The materials you need are:

If you buy the wood at Home Depot or Lowe’s usually you can have it cut for free.
Have each of the pieces of MDF cut to 24″ x 24″
Have the 2×4x96 cut into 4 24″ pieces.
Have the 1×4x120 cut into two 24″ pieces and two 26″ pieces
Have the 2×4x120’s cut into 6 40″ pieces. (lower if you are short, 30-36″)
If you go with a 36″ height, you can use 3 2×4x84’s to have less waste.
If you go with a 30″ height, you can use 1 2×4x120 and 1 2×4x72 to have less waste.

First step to assemble the table.
Take two of the 24″ pieces of 2×4 and one of the pieces of MDF.
Run a “healthy” bead of liquid nails along one of the 2×4’s, then set the MDF on top of both 2×4’s.

Take a 3/16″ drill and drill 8 holes, evenly spaced along the side,
trying to be as close to the center of the 2×4 as possible.
Then take a 3/8″ drill bit and CAREFULLY drill down about 1/16 in to allow the screws to counter-sink.
Working from the center, screw in the wood screws in an alternating pattern,
working outward. (center, left, right, left right, etc)
You’ll see some of the liquid nails ooze out.

After you are done with the wood screws, simply spead the excess over the gap.

Repeat for the opposite side.
Tip onto the side, and take one of the other 2×4x24 pieces and
place on top of the sides of the two 2×4’s already attached to the MDF.
take a pencil and run along the inside of the 2×4 as shown.

Cut on the “outside” of the pencil line so the board is slightly larger than the measurement.
This needs to be a VERY tight fit, otherwise it will leak vacuum.
Once you have both 2×4’s cut, run a “healthy” bead of liquid nails along
the MDF and the sides of the two 2×4’s already mounted.

You may have to gently tap in the board with a hammer to ensure a snug fit.
Once again, some of the liquid nails will ooze out of the joint.
Simply spread the ooze over the joint.
Repeat the pilot/counter sink drilling and screw in 6 wood screws,
again working in an alternating pattern.
By this point you should be used to liquid nails oozing all over.
Once you have all four pieces of 2×4 secured, go ahead and wait for the liquid nails to cure.

Flip the assembly over and run a “healthy” bead of liquid nails along the edges of the 2×4’s
then place one of the other pieces of 24×24 MDF on top of the 2×4’s.
Have a helper assist you with keeping the MDF squared to ther 2×4’s
and drill the pilot holes and counter sink holes.
When screwing in the wood screws, work in a “star pattern” starting in one corner,
then moving on to the oppposite, etc.
Once again, smooth over the oozed out liquid nails. then wait for this stage to dry as well.

While you are waiting, take a piece of the 24×24 MDF, a pencil, and a piece of scrap 2×4.
Place a 2×4 on the corner and mark around with a pencil.

Do this for each corner, then cut with a hand saw or radial saw, etc.
Once the box has dried, we’ll attach the legs, braces and bottom plate.
Pick which side of the box you want to be the top, and flip that side onto the ground.
mark pencil lines from each corner, making a center mark.
Drill a 1/4″ hole at this center point, then using a 1″ spade bit, drill a 1″ hole in the center.

Place the 1″ floor flange aligned with the hole and drill pilot holes for the wood screws.
Also pencil the outline of the flange at this time.
Before screwing on the flange, put a good amount of liquid nails inside the pencil circle.

Next, Have a helper hold one of the 2×4x40’s straight and level and make your pilot holes for the wood screws. Put a generous layer of liquid nails over the mating surfaces, then screw together.
On one side you’ll only want the 2×4x40 to overlap the box by half it’s width.
Make sure the clean the excess liquid nails from the resulting corner.

After all legs are assembled, flip the table onto the legs.
Take a measuring tape and measure 5 inches up each leg and make a pencil mark parallel to the ground.
Have your helper assist you with holding one of the 1×4x24 pieces against two of the legs,
making sure the 1×4 is level. Align the top of the 1×4 with the pencil mark
Drill pilot holes, and if desired, run a line of liquid nails along the mating surfaces before screwing in the wood screws. Repeat for all four sides.

place liquid nails or wood glue along the top surface of the 1×4’s and place the notched 3/4″ MDF on top of the 1×4’s.

TADA! Looks like a table at this point.

Here is a shot of a quick “test” fit of the vaccum surface.

Part Two will highlight the assembly of the heater box.