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In a message dated 1/8/2007 10:11:12 PM Central Standard Time, ShellyDalg@aol.com writes:
and minimize the pockets you can't reach with paint just my two cents. I tend to agree with the kiss rule here. My design
started using both internal and external ribbing, thinking I would save money.
the further I got into it the more I realized, just use the thicker material and
be done with it. The mfgs I provided can handle just about any thickness
ya can imagine, my brother was involved with one pressure vessel that was
6 inches thick12ft wide and over 30 ft long (think that is a little out of my budgef)
one thing that has been discussed of late is rust. This is an area I
have played in since I was 14 started doing body work at a body
shop.
Few hints on paint.
First and most important is clean clean clean
Welds I would sugest grinding as smooth as possible
next sand blast with glass beads.
And the most important part use a metal prep cleaner.
This can be bought at any body supply store. It is usually
not much more then watered down hydrochloric acid. This will stop any
oxidation going on at the present and actually etches the
metal for a mechanical bind for the primer.
2 don't think more is better. You need to seal all the moisture and
air from the area, but too much is not good. Paint and other materials
expand and contract at much different rates. This constant uneven
motion will either crack the paint (if to brittle) or break down the
chemical and mechanical bond.
A poorly prepared rust area will rust thru, faster being covered incorrectly
than if it were just left bare. Look at bare metal left out in the elements
it surface rusts real fast, but will take many years to make any real
structural problems. Now look at how fast a fender can rust all the
way thru on a car.
Also be careful about the paint itself. Not all paints are water proof
these will quickly break down.
Another point is any drilled hole. the bare edges have to be taken care of.
When tolerances are a concern I have used gun bluing and has worked
pretty good. Bolts need to be painted in place and don't use lockwashers.
They tear up the paint underneath and will give you the ugly little rust
flows in days.
The last I will mention is rubbing panted surface. The best way I have
found is, say on the pivot pin on a hatch. glue reinforced nylon washers
at the contact points, this will give it a great deal more life than just
letting the painted surface rub together. The trick here is the glue
to washer, can not allow the washers to rotate.
Dean Ackman
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