G/F class lakester in Wichita, Kansas

[ggl205]

Making the fin taller and extended more to the rear may help your high-speed stability, John.

Regards, Neil  Tucson, AZ

Neil, I almost left the tail fin off given experience with my first car. There is quite a bit of flat from roll cage back and I spent quite a bit of time getting my Cg as low and far forward as possible so I didn't think I needed the fin for additional Cp. But I reckoned it wouldn't hurt having one even for a little extra insurance and the car is, after all, an LSR so why not?

John

[ggl205]

We had some glass that would not quite cure.  Months later we put it outside and let some summer heat and UV work on it after 3 days it no longer "seemed" green

That is good to hear, Sparky. I tried to be as careful as possible when weighing resin and hardener but some batches were a little over the 4:1 ratio. Oddly, the first batch was way over on hardner and it cured just fine. That is not supposed to happen with epoxy.

We get some brutally hot 105 days out here so I should have good opportunity to bake the glass.

John

[Seldom Seen Slim]

John said:  "... we will extend the polycarbonate forward until we get it right."

SawZall to the rescue!!!!

[Stainless1]

Good forward vision is way over rated, there is not a lot to look at 200 feet in front of the car... everything you need to see is a 1/4 mile away and coming at you fast! 
Car is looking good John, I will drop by soon 

[mc2032]

" good forward vision is overrated",  shoot i keep my eyes closed during most of my passes.  Stainless says i need to work on my tuck.  i built the motor on the bike, a potential steaming pile of shrapnel, i am usually in a flinch which kinda looks like a tuck only longer   i don't care that my eyelids are only a 12th of an inch thick, they have to slow something, anything down.

[ggl205]

Yesterday, my crew was really motivated and put down three additional structural layups making a total of four. All the way through this process, I had my doubts. I wasn't sure .030" ABS sheet would be enough to hold form unsupported. I wasn't sure if chemicals used would react negatively with ABS. I wasn't sure at all that we knew what we were doing but as the old saying goes; in for a penny, in for a pound, so we soldiered on. The end result, after four layers of 7500 Hexcel 9 mil mat and Axon epoxy resin/hardener, we have a very strong and straight shell with only a hint of where we overlapped seams. I am completely satisfied with the result and after a week or two, will begin sanding and filling low spots and irregularities. With a little more luck, we should have a body for the Lakester before winter ends.

Ross, all those nasty looking seams you asked about all but disappeared after the last layup. Kind of surprised me too.

John

[Seldom Seen Slim]

" shoot i keep my eyes closed during most of my passes.  Stainless says i need to work on my tuck.  i built the motor on the bike, a potential steaming pile of shrapnel, i am usually in a flinch which kinda looks like a tuck only longer   i don't care that my eyelids are only a 12th of an inch thick, they have to slow something, anything down."

Geez, that sounds familiar.

[ggl205]

I am at the filling/sanding stage and surprised how smooth overlapped seams now appear. There are four layers of 9 mil 7500 Hexcel mat (five layers when talking about overlapped seams) and glad we went with the extra lamination. Sanding takes one layer down to the next for high spots but yields a very uniformly smooth surface (see image). I did find a number of depressions where glass cured with distortions. Before asking the forum what products they used to fill with, I went ahead and tried Bondo Glass to fill these low spots. This is very nice, fiber reinforced filler putty made to be used on fiberglass (metal too). Once this product is consumed, I will switch to Everlast products. Everlast has a similar product to Bondo Glass but can be had in larger cans. Everlast was recommended by a fellow forum member and has a wide range of professional grade fillers and putties.

John

[Ron Gibson]

The Bondo Glass and others like it are to add extra strenght. If the panel is not weak or thin, regular filler will work fine and is about 500% easier to work and get to the finish you need.

Ron

[ggl205]

The Bondo Glass and others like it are to add extra strenght. If the panel is not weak or thin, regular filler will work fine and is about 500% easier to work and get to the finish you need.

Ron

Ron, the body shell is super strong. I just wasn't sure at the time if regular Bondo was up to the task of filling low spots of up to 1/4" without cracking or crumbling. Enough of you who have had successful experience with regular Bondo over fiberglass has convinced me to use it as a skim coat to smooth out small surface irregularities. I plan to wrap the body instead of paint so normal surface prep reserved for paint will not be needed.

John

[Freud]

Every imperfection in the body will show thru the wrap.

That's from the experience of 4 wraps on Target 550 streamilner.

FREUD

[ggl205]

Hi FREUD:

Yes, and that is why I am trying my best to make the body as feature perfect as possible. I guess I will have to ask the wrap guy how he wants the surface finish to be. There is still one more lamination of 120 Hexcel mat to go down after imperfections are taken care of. It is a finishing mat but heavier than normal (9 mil). After that lam, more sanding.

Did Target 550 streamliner have any trouble with wrap coming loose at speed? I can only imagine what would happen if any high speed air crept under the wrap.

John

[Ron Gibson]

If the panel doesn't flex much, I wouldn't worry about 1/4", especially if you are putting on another layer of fabric.

Ron

[ggl205]

Ron, you are probably correct about Bondo supported by the last lamination of glass. I will let you know in a few weeks.

John

[MAYOMAN]

John, that 3D rendering looks quite nice. With that tiny vertical stabilizer, your excellent side vision might be more important than the forward view. Hope to see you out there this year.