Ill see how my next enclosure goes, and ill post new pics. Its allready wrapped and ready for sanding, just waiting on a nice day = ] thanks guys

 

you have to be carefull going that high before the final coat of paint is applied. you could go to 6000 if you wanted to on clear, or the colour coat, but going to 2000, and then applying paint is not the best way to do it, because paint needs somewhat of a scuffed surface to adhear to.

I wouldn't bother going higher than say 600 unless it's your final coat, on the final coat, or clear go as high as you like.

Mark

 

There's kind of two posts going on here. How fine a grit you sand with will affect texture and thus the finish. He is having a problem with getting the surface level. That is a technique issue. Always always use a block or some kind of form for the paper. Freesanding with your hand only will lead to all kinds of ripply panels.

I try to use zero filler. Ultimately some will need to be used but I would expect on a box like that to use almost none - maybe a couple of ounces. Could probably get away with just spot putty.

Oh and for heavens sake - avoid at all costs the temptation to add filler and resin together and slathering that on the outside of a fibreglass piece. That is almost sure to result in excessive sanding which usually results in ripples.

 

the finest grit we use is 150. Proper design will always work better. The biggest problem we find is using too much hardner and the glass curing too quickly. It's much better to let it cure naturally over a number of hours than having it cure in 20 minutes. It looks like you're on the right track and there's nothing like hands on experience. I've thrown out so many boxes it makes me sick but I've learned something from all of them.

Keep trying, it'll come!

 

A good trick is to use a guide coat. After the initial shaping is complete, spray a thick coat of grey primer, them a "fog coat" of red primer.
when you start to block sand, you will quickly see the high spots turn grey, and then break through to the filler below. The low spots will stay red.

Once you break through to the fibreglas, STOP sanding! Any further sanding will only remove more of the soft filler, and softer primer, deepening the low spots. You now must choose to either lower the high glass with a grinder, or fill the red low spots with filler or high build primer. Repeat this process, and stay with the heavy grit, until the red comes away uniformly. then do it again with the next higher grit.

The biggest temptation is to hurry on to a finer grit, but stay with 40/80 until it's perfect.

Using this method will show all the tiny imperfections, and sanding marks in contrasting colours.

When using a block, always keep the long side of the block lined up with the lowest "crown" ( the flattest part of the piece).
For inside curves a small rubber block is required, but for outside curves and flat parts, stay with a solid block.

Also important to thoroughly blow off the piece before applying the next coat, to remove sanding dust from the pits.

No need to go higher than 320, until the final sand before paint.

 

I think you just solved my problem Starterwiz= ] I had never thought of using a guide coat for breakthrough. It was allways a guessing game. Unfortunately I was only using "spraybomb" type paint for priming and finishing.. Im going to Pick up a proper spray gun this weekend, and start playin with that. What types of primer and paint are suggested, automotive of course. But do any have benefits ? = ] Thanks ~ Nelson

 

I use regular high build primer in grey, and a spay bomb for the red fog coat.
A lot of people say that the 2 part epoxy primer is better and stronger, but I've not seen that the extra cost and having to clean out the gun every time is worth it, especially since these are "interior" pieces.
Fillers should be used according to the level of removal.....Start out with the strongest fillers (duraglass), move next to a good bodyfiller (rage gold), then into the softer fillers, two part putties, and finally the primer.

The thicker the coats of softer fillers, the more chance of cracking, shrinking, and chipping later, so the less you have to fill with primer, the better.

A difference of the thickness af a single thin layer of paint will be very visible on a high gloss reflective finish, and will be seen as a distortion of the reflection.

There are also spray-on coatings that can speed up the process (Fibrefill is one I've used) that can be applied up to 1/8" thick.

The ultimate finishes are the result of correct blocking techniques. I always keep the block lined with the lowest crown, and sand in an "X" pattern across the line.
Invest a few hours watching a master body man block a Jag, and you'll get the idea.