Body Work Help - Building an Edge

[evvander11]

What product would you use to build an edge, for example on the door. I would think body filler would be brittle in this application. What about building up the door sides to match the body?

We have been told to use a west systems epoxy but I am unsure if this is compatible with every body filler...

Can someone give me a quick breakdown of vinylester vs polyester? Also, would something like 3m HSRF work for an edge?

[edwardb]

My responses based upon studying this forum and other sources, years of doing glass work in other hobbies, plus doing most of the body work on my Mk3:

- Epoxy (West Systems or otherwise) really has no place in body filling. You could arguably use it for bonding purposes (hinges, brackets, whatever) but has worked for some, not for others. Not everyone will agree with this, but the party line is to use vinylester products with the vinylester FFR body.

- HSRF, while an amazing product (and I used quite a bit for repair and bonding) you really don't want to use it for body filling either. Other than perhaps the parting line repair. It's rock hard once it sets up, and is nearly impossible to sand.

- Within reason, body filler (Rage Gold, etc.) is fine to build the edges, match panels, take out waves, etc. For the doors, work hard to get them lined up as best you can without any filler, e.g. adjusting the hinges and striker, adjusting the lower body in/out, etc. That way the body filler is minimized as much as possible.

- If you have a really large edge to build up, e.g. you trimmed the door too much, you may want to build up the edge first with vinylester resin and glass matt. No question that would be stronger. Then finish with body filler.

- Vinylester is very common for boat building and repair. Tons of products out there at boat and marine supply companies.

Good luck!

[BigLeo69]

duraglass, got mine from Eastwood, if you build up around the door opening on the body, clean and scuff really good, i drilled some 1/8" holes into the body maybe about every 3" cleaned them and put the green lead in, it will push into the holes and bond, the little bit that oozes out on the inside will be covered with the door sill. to make it easy i taped off the door and body around the area to fill taped the edge of door to keep it off then filled it around the perimeter working fast pushing it in and ran a 3/16" drill bit around the door opening, pulled the the door open removed all the tape and did a quick form to check fit.
a body file works good on this stuff if it gets too built up and sets on you, you can also cut away with a blade while its curing.
its held up to road and rain for 4500 miles and no movement
i only had to do it on the drivers side it seemed to be my passenger side fit the best and drivers was to big for the door to fit.
good luck i am still in primer hope work goes well this winter and i can be in paint for the spring.

[evvander11]

What about this product?

The edge i am building isn't large at all, maybe adding 1/8" of an inch where the door was trimmed to short from the factory. I'm afraid that body filler would be too brittle for this, and glass matt and resin would be overkill for that application.

[Greg_M]

That will work fine and I used it where I added more than 3/16" to build edges. FWIW, I used just Rage for doors, hood, trunk, rolled cockpit edges less than 3/16" and it's been fine for many years now.

Greg

[G-Pete]

Look at this may this help you a little further....

How to Repair Fiberglass - YouTube

How to Repair Fiberglass - YouTube

[COMPETITIONCOBRA]

The only product described below that I would use is HSRF but I feel that is not the best way to build up an edge. I also had to build up areas on my doors that were trimmed too much and the only product I used was vinylester fiberglass resin and mating. I determined first where the areas needed the attention and at what length the addition needed to be.
I used the random weave mat cut into strips about 1/4" wide by about 6" long and laid them on the area to be built up one at a time. These are tricky to lay up because they tend to want to slip off and the strips tend to tear so patience while doing this is a must. I found that about 4 layer of glass was the maximum at any time because with the resin and all the dabbing and positioning tends to make the mat squirm around and not stay positioned but with practice it will get easier.
In the photo below I built up the top of the door edge about 1/4" with this procedure.

[cwrandolph]

See this link - post #2. I used a Dremel with a cut-off wheel and filled with HSRF. It's very strong.

making doors larger

[convincor]

Dura-glass, short stand filler, and others like kitty hair are polyester base products and really shouldn't be used IMO.
3M HSRF is the only filler that is vinylester resin base same as the body.
Yes, hard to sand but at this stage you can machine sand with disc or belt sander with 40 or 60 grit. Then use your body filler which shouldn't be any more the 1/8".

[BigLeo69]

Originally Posted by convincor

Dura-glass, short stand filler, and others like kitty hair are polyester base products and really shouldn't be used IMO.
3M HSRF is the only filler that is vinylester resin base same as the body.
Yes, hard to sand but at this stage you can machine sand with disc or belt sander with 40 or 60 grit. Then use your body filler which shouldn't be any more the 1/8".

poly works
as does the vinyl-base bondo

[convincor]

Originally Posted by evvander11

Can someone give me a quick breakdown of vinylester vs polyester? Also, would something like 3m HSRF work for an edge?

The Resin Families: Epoxies, Vinylesters and Polyesters

"Vinylesters represent a resin development step in the right direction. While still utilizing a polyester resin type of cross-linking (i.e. peroxide cured). These hybrid resins are toughened with epoxy molecules within the backbone. Shrinkage is less of a concern with vinylesters and prerelease of the part from the mold is reduced. The toughening effect of the resin modifications makes for a better resistance to micro fracturing and some of the secondary functionality of the backbone assists in adhesion to substrates. Vinylesters are capable of forming secondary bonds around 500 PSI "

"Polyester has the advantage of being extremely inexpensive when compared with other thermoset resins i.e. vinylesters and epoxies. If the upside is cheap pricing, the down side includes poor adhesions, high water absorption, high shrinkage, and high VOC's."

[evvander11]

So after seeing that breakdown one would assume that vinyl ester products would be the way to go. Correct?

The body is definitely vinyl ester?

Is the Rage filler vinyl ester as well, or is that not really a concern?

[BigLeo69]

maybe this will help:

http://www.ficicomposites.com/FICI_Resins_Web.pdf

mixing Vinylester and Polyester?

rage is a poly base but everyone uses it


the vinylester if you are applying to the gelcoat, but the body gets scuffed and the face gets removed.
vinyl ester is more chemical/h2o resistant and a bit stronger.

but the duraglass is very strong too just has less water/chemical retentive
but then again we aren't throwing chemical on our sealed paint and body.
maybe i just sucked up too many VOC's

[Tennessee Tim]

I haven't seen this mentioned yet - for building edges, I used Evercoat's Euro-Soft. That's exactly what it is designed for. Good stuff.

Tim

[convincor]

Originally Posted by evvander11

So after seeing that breakdown one would assume that vinyl ester products would be the way to go. Correct? CORRECT
The body is definitely vinyl ester? CORRECT


Is the Rage filler vinyl ester as well, or is that not really a concern?
No, Rage is polyester. Rage is for fairing out/ MINOR shaping

Originally Posted by Streetrodpainter

the layup on the ffr body is vinylester based. the gelcoat is polyester based. holes, voids, deep grinding etc the protrude into the layup use HSRF. for minor shaping, fair out with a polyester based product like Rage Gold. cheers, SRP

While some feel the need to argue the point the the polyester products will work, it doesnt mean it's the right thing to use. The point of being more resistant to chemicals and water is irrelevant. What is is the fact that it has better adhesion and is less prone to shinkage.

Originally Posted by BigLeo69

the vinylester if you are applying to the gelcoat, but the body gets scuffed and the face gets removed.

WRONG. vinylester should only be applied to the bare glass. Gelcoat needs to be ground off.