Questions on fibreglass techniques

Chris,
A great source of composite fabrication is the home built airplane community. I built a Long-Ez which is fiberglass/epoxy over foam core. See if there is anyone near you building a composite plane an volunteer to help them do a layup. It is not that hard to learn and there are a lot of tips to make it easier. They will know the local sources or epoxy, glass, tools, filler, etc.

There are some expoxies that you can get from local boat stores and I can provide info on that if needed.

Hope this helps.

Steve Rothert

 

[Guest]

John,

About the Spyder.... Schweeeet!

 

Lynn,

Ta very much!

John S.

 

[ChrisL]

Hi all,
Just letting everyone now that I'm furiously taking notes. There seems to be a wealth of knowlege here. Keep it coming.

Steve,
What a great idea. I do in fact know a very keen home aircraft builder who I usually see once a year at a buisiness forum. We usually end up comparing notes on on our hobbies, but the subject has, stangely, never turned to bodywork???? I think I'll email him this week.

 

[ChrisL]

It sometimes pays to mention that you're buying for a GT40 project.

After having taken note of all the suggestions on this post, I made my way to the nearest WEST distributer.

Being in the middle of the Holiday break, most stores were closed, but his one was open. The well dressed gentleman behind the counter was more than interested in my project, and spent a considerable amount of time discussing my options... and somewhat keen to give me discounts at the end!

He seemed extremely knowledgable, but quite lost when it came to doing the ordinary things like using the cash register. Consequently, I asked him if he was a fill-in employee. He replied... "well sort-of. I'm the Managing Director of West Australia and couldn't convince anyone to work though the Holiday break, so here I am".

Good to know that he's hands-on.

Incidentally, the fibre-glassing on the GT40 is progressing well.

 

[Bill Hara]

Chris, I didn't know that the West Australian Premier was calling himself "Managing Director"

 

[ChrisL]

Bill, It seems these polititions have their fingers in ALL the pies

 

[Clive C]

Hi all,

You guys are a tonic!

Need some advice. I have a fairly reasonable body, but the doors are far from perfect, and have about a 6mm/1/4 inch suck=in through the centre/bottom. I had considered "bogging" it, but there has to be a better way.

These panels have been made of an inner and outer and are as strong as! No way can I separate them, tweak them straight and re-bond.

Has anyone got any suggestions how to perform a strong, composite filler to do the job.

cc

 

[40 Bud]

1/4" inch is a lot of filler. However if you have to fill, try Corvette Panel Adhesive/Filler (type 3). It is very hard when set and can even hold up on corners. It is more work to finish because it is hard but it is not loaded with talc type fillers and adheres very well. I have been using it on a reworked double nostril panel and am happy with it.

 

[Peter Delaney]

CC, I would seriously look at doing that sort of build-up with chopped strand mat & resin, rather than "bog". Its not hard - you just start with a small piece in the deepest area, then a larger piece, & a larger piece, etc. You'll probably need up to 10 or 12 layers to get 6mm. Don't forget to consolidate every couple of layers with a grooved roller. Blocking back is a bit of work with 80 grit on a long flat stick, but the result will be bullet-proof. Patience & long strokes in each diagonal direction will get you the right result. (I've just finished doing this to mine, although it was the front door edges, tops & sides, that need the build-up.)

Kind Regards,

Peter D.

 

[Hershal Byrd]

CC,
You can also take a wafer wheel on a die grinder and seperate the two halves that way. Then you can reset the outer skin to where you want it then use duraglass short strand filler to bond it back.

Hersh

 

Peter, If it's a deep area, I would make a filler using 'glass bubbles' mixed with resin to make a putty, sand to shape with a long board #80 grit, then put a layer of chopped strand mat over the area, sand again with #80 grit, touch up with ' flowable glazing putty ', prime and you are reddy for paint. Why the 'glass bubbles'? it makes a very light weight putty and it's easy to sand, even when you mix it with epoxy resin.

 

[Peter Delaney]

Bill, the "micro-baloons" are great - I have used them with resin as you describe on smaller areas with not much surface stress.

My comments re the mat & resin for larger stressed areas come from the experience of a mate of mine who is doing up my '71 Vette (basket case to decent car in 5 years !). He has been in the business for 20 years & has tried just about everything. His advice for me on the '40 was :

- If the defect is less than the size of a match-head (pin-holes, etc) - bog is OK as long as it comes from the paint manufacturer & is therefore fully compatible.

- Non-stressed filling - use resin + microballons.

- Big or deep areas - grind everything way back to raw glass & use lots of mat + resin.

This advice has cost me weeks of extra time, but I think that its worth it to avoid having a big chunk of bog fall on the ground when I slam the door !!!

Kind Regards,

Peter D.

 

Sorry if my USA accent is showing, but I have a dumb question. What is the American translation of "bog"?

Jim Seisser

 

[Hershal Byrd]

Jim,
I believe it is Body filler, Bondo, mud, and I bet they call it something else in the UK....

Hersh

[ February 07, 2003: Message edited by: Hershal Byrd ]

 

[Peter Delaney]

Hersh, you are right - down here in Oz, we call it bog, but it is the same as Bondo, Body Filler, etc. When used to excess, it is internationally recognisable, regardless of local name, as that big lump of crap that falls out onto the floor when you slam the door hard enough !!!

Kind Regards,

Peter D.