Allowable thickness/Bondo Glz and Spot?

[talkin Monkey]

A quick question as to how thick you can safely lay up Bondo Glaze and Spot putty on Fillets to those in the know.

Would an 1/8 inch in thickness around the forward and trailing root edges be pushing it?

I think the fillets are built up enough to survive a small nuclear blast. Just want to pretty up my sloppy learning curve without adding more liquid epoxy.

I have some "Pig-Putty" (a stinky 2 part clay) I could use, but am not sure how well it sands.

I like how easy the Bondo is to apply,sand and shape, but would hate see chunks missing from the fillets when I recover the rocket after flight.

Thanx, Scott

 

[kandsrockets]

Rule of thumb with spot putty is no thicker than your finger nail. Anything thicker will probally crack of fall off.

 

[D-12 Dave]

I agree with KRS,plus you want to watch the weight,on the models I've used it on they finished a little heavier than i would have liked.

 

[talkin Monkey]

I'm a long ways from a fingernail away. Think I'll bench test some Pig Putty on a cardboard box or something.

Thanks for the advice guys.

Scott

 

[kandsrockets]

I'm a long ways from a fingernail away. Think I'll bench test some Pig Putty on a cardboard box or something.

Thanks for the advice guys.

Scott

Here is another option. Go to your local auto parts store and look for micro lite or lite bondo filler. This is not that heavy and sands very easy. This you can build up your problem areas. Then use your spot putty to take care of those minor scratches and dings

 

[new2hpr]

Even regular Bondo shouldn't be used at 1/8" thickness if any flexing is expected. It will crack and fall off. The glazing putty should be much thinner than that.

If these are epoxy fillets, next time try the (implement of choice) dipped in alcohol and run across the fillets to smooth them out. I've used PVC pipe. Others like plastic spoons or gloved fingers.

Ken

 

[talkin Monkey]

Even regular Bondo shouldn't be used at 1/8" thickness if any flexing is expected. It will crack and fall off. The glazing putty should be much thinner than that.

If these are epoxy fillets, next time try the (implement of choice) dipped in alcohol and run across the fillets to smooth them out. I've used PVC pipe. Others like plastic spoons or gloved fingers.

Ken

Problem is, is that I tried all the above plus a pumpkin scoop tool on different fin fillets AND different epoxies to cover up/build-over the previous mess ups. I just didn't do all the above smartly or consistantly.:monkey:

Will play around with some Pig Putty (A 4th epoxy) tonight and see if it's a viable option. The fins are anchored like an aircraft carrier at this point, just want to recover the cosmetic value that I originally intended.

Hind site being 20-20, I should have applied the initial fin to BT fillets as consistanly and perfectly as possible and lightly built up over any imperfections from there instead of a "Gobb it on, I'll sand through it later mentality".

I'm sure someone will ask, so here's the recipe for those who are really into sanding the crap out of fin fillets: (AKA, not the way to do it):kill:

1st: Apply small amount of PML 30 minute epoxy as a base fillet with syringe to all twelve fins.

2nd: Purchase several LokTite sets of 60 minute epoxy and apply using a plastic spoon on 1st set, a latexed finger on the 2nd set and finally a pumpkin scoop on the 3rd. (Each "Smarter" at the time...sequentually)"

...Sand like a maniac....Uh Oh...need more epoxy, still not all there yet.

3rd: Apply TCC-5220 A/B Fast Patch Paste TCC-52 A/B like a madman. (This oughta take care of it, even smarter yet)

...Sand with 7/16" dowel and 40 grit...WOW! These big Patch Paste fillets are are like like sanding Obsidian!...Still not "There" yet!...

4th: Apply "Pig Putty" to recover those "Perfect Fillets" that were originally intended...Maybe...

---Unless you are a licenced professional monkey on a closed track, do not try this at home---:lol:

:monkey:Scott:monkey:

If someone can learn from your mistakes, why not share them?