nocones
nocones PowerDork
7/5/22 12:04 p.m.

I have done a lot of work time on the car in the last four days but the actual progress is less.  

Picking up where we left off I had to do the Copy+Mirror+Paste on the rear fender to finish off the drivers side.  It went pretty smooth but start to finish fully welded and planished it takes about 5 hours to make each fender.  I also went back and finish welded the passenger fender and planished it.   Welding the stock sheet metal onto the conduit took quite a while.   Mostly because the stock sheet metal is ~24 ga and has light rust so burn through happens a lot.   

Next step was to work on the inner fenders.  Long term the plan was to make these out of fiberglass so they could have curvature, but I figured that since I had never done fiberglass it would probably take much longer so I will do steel for now (foreshadowing more on that later).   Based on my experience with welding the sheet metal to the conduit I decided I really didnt want to make the inner fenders permanently attached so I added tabs for rivets to hold them on.  

I cut the top piece and clecod it in place and made the flat inner wheel part.  For this piece I put a flange on it that I planned to spotweld to the rest of the inner fender.   Then it was just a matter of holding the builders board against the pieces and triming it to fit.   

The board was transferred to 22ga sheet and welding comenced.  There was enough form to this joint that welding didn't really distort the panel.  I did several passes of tacks starting about every 4" then filled in between them until I had a tack every 1".  I then welded between the tacks in ~1/3" beads.  It worked reasonably well but still resulted in occasional blow through. 

I didn't take pictures but my method for dealing with blow through is as follows: if you try to weld a continuous bead to close it you wind up chaising the blow through and just making a bigger hole.  The trick I found is to reach over and turn the wire feed up a bit and then do a series of instantaneous tacks around the perimeter of the hole.   This leaves a small weld bead around the hole.  Then you can slowly weld the hole closed with more continuous bead.   The weld deposits around the perimeter provide enough heat sink to keep the blow through from spreading.   Remember to give the weld a good whack with a hammer and dolly to expand it slightly and reduce the stress in the metal around your air welded hole.   

I'm sure this is "bad" but it worked for me, and planishing these spots out when finished revealed no voids in the filler. 

So after welding the inners they where planished.  I still need to weld on 2 additional tabs on the driver's side and clean up the front but overall I like them and think they work reasonably well aesthetically.   I would like more curvature on the back but the front actually works well because the stock fenders are so vertical at the front. 

That was 3/4 days that I worked.  Total of was about 18 hours of work.  Day 4 will be documented next post.   

nocones
nocones PowerDork
7/5/22 1:18 p.m.

So I moved back to the front fenders and proceeded to weld the fenders to the conduit and finish weld the flares.   In honor of Gumby I tried to TIG weld these.   For the fender flares the TIG did an excellent job.  Much faster with less clean up then lots of tiny MIG welds did the back.   For the fenders to conduit weld the TIG didn't work well.   

It was then time to start the inner fenders.   I followed the same process as the rear and made a top then attached the next piece.   I fully welded this joint and then my inner fender promptly turned into a wavy taco.  It just didn't have the rigidity to resist the stress from the welding.  No amount of smacking the weld would bring it back to shape.   So it was time to overcome my irrational fear of composites and try fiberglass.  

I've never done this before and my technique I'm sure is not "correct" but here is what I did.  

Since the fiberglass can literally be any shape I want I was able to make it have a more rounded shape.   To do this I used some 1/4" foam that came with the last appliance I bought and used spray adhesive to hold it on.   I used 2 layers to make a 1/2" crown.  

I cut the foam with a saw blade to be even with the adjacent panels. 

Then I used a flat bastard to smooth it to the shape I wanted.   

Once shaped the entire part and ANY spot that the fiberglass would touch was covered in clear packing tape. 

 

I used magnets to hold my chopped strand mat while I trimmed it roughly to shape.  The first part I did not put relief cuts on the inside and it was definitely easier with the cuts to make it lay flat.   I cut 2 layers of CSM to be ready for make a 2 layers part.   The mat I am using is 6oz per yard and for a reasonably well supported part 2 layers of 6oz seems about right.   

Make sure you put plastic everywhere to prevent a mess.  The resin tends to get everywhere because you have to move pretty quickly.  

Then it was time to lay up the part.  I'm using Bondo brand fiberglass resin because it's what was available locally and I bought 3 gallons in March for $34/gallon.   It's up to about $45 now.  "Good" resin is closer to $60-70 + shipping.  I'm sure they are better somehow but this worked.  

My part is about 4' long and 18" wide.   I initially mixed up 8 oz of resin.  This was enough to almost saturate 1 layer.   The pot life of the resin is about 10-15 minutes.   I mixed it about 95% of the hardener because it was 90*F and I wanted a bit slower cure.  That said I was counting 80-100 drops so I'm sure I messed up the volume some.   

I don't have pictures of the actual layup because I was busy and I didn't want to get my phone all messed up.  I brushed a thin layer of resin on the entire part.  This resin holds the mat to the part when you initially lay down the mat.   I then using a combination of pouring and brushing worked resin into the mat.   I did a minor amount of roller work to smooth this first layer.  The mat is rigid and difficult to form until the resin disolves the binder.  Then it contours easily.  I kept adding resin until the matt strands could no longer be seen easily.  Once the first layer was mostly weted I layed the 2nd layer on top.   I then rushed over and mixed another 10 oz of resin quickly.   By the time I got back to the part the first resin was still workable but had started to harden.   I rolled the part again to smooth it to try to ensure the first layer was the right shape.   I then repeated the pour, brush roll until the part was saturated and no mat strands where visible.   I added a couple small pieces of mat where there where low spots or gaps in the mat.  I then just kept rollering the part until the resin started to cure.   

I left the parts in place for about 1.5 hours then I demolded them.  They separated really easily from the tape.  I used a Dremel with a cutoff wheel while wearing a N95 mask for dust to trim the part.   And that was it.  My first 2 fiberglass parts.   Overall with prep each part took about an Hour.  Layup was 20 minutes.   

Supplies wise I had gloves, a real respirator, a chip brush (cheap paintbrush to throw away) and a graduated paint cup.   I used random Amazon CSM I got for $4.50/yd 54" wide yards and the Bondo Resin.   The most important tool I had was a resin roller.  I'm sure you can lay up the part without it but after using it I wouldn't try.   The roller does a good job smoothing the matt and pushing the resin around to make even saturation.   Without it you have to stipple the part with your brush which is slow and would seriously limit the size of part you can lay up.    

I was surprised how "easy" the parts where to make and how rigid the 2 layers of CSM are.   I figured I would have to reinforce the parts somehow but just the line of rivets on the top seems to be enough.   Each part is .6 yards of mat and 20oz of resin so $8.01.  The surface is rough and will require a small skim coat of Bondo before final paint.   

maschinenbau
maschinenbau UberDork
7/5/22 1:57 p.m.

Nice parts! I too have not yet taken the plunge into composites, but I am excited to learn from you doing it first. Even though you laid up on top of the metal fender, the part still fit flush to the surface? 

Also you might as well lay up the whole body for a mold at this point. Then you can subtract all your steel and conduit from the budget...just saying...

nocones
nocones PowerDork
7/5/22 2:03 p.m.

In reply to maschinenbau :

Your right it would be pretty easy to mold parts at this point.  Eventually fiberglass or carbon fenders will happen.   But for 2022 the steel will remain.   

There is a little ridge where the fiberglass sits.   I'll taper it slightly but want some thickness for strength.  I will need to put black silicone on it at the joint for proper flare goodness 

StripesSA1
StripesSA1 Reader
7/6/22 12:37 a.m.

In reply to nocones :

A couple of tricks my dad taught me when using CSM. 

After measuring your project size, don't cut the CSM to "size", this includes your overhangs.

Rather cut sections to make your project size, with over laps over each other, and that works for your second layer aswell.

Then you take your CSM patches, and your tear them thinner, ie you essentially are making a "2-ply" toilet paper a "1-ply". This way it will shape easier on contoured surfaces and your resin will saturate the CSM quicker.

Now a tip I did not try, but got from surfboard builder was, when cutting of those floppy edges, wet it down with some water, and you will get less itchy powder all over. This is unconfirmed, so I don't know if it will work.

The other tricks with the CSM is confirmed, as I had build a couple of fibreglass seats for a dune buggy I had many years ago

 

Edit to add: you also want to criss-cross you "1-ply" patches, and makes sure the overlap each edge for additional strength

sleepyhead the buffalo
sleepyhead the buffalo PowerDork
7/6/22 9:15 p.m.

for a better surface finish on something like those fenders, you might look at adding a layer of peel-ply on the outside and then working the roller to pull resin through it.  When you peel that layer off, it should leave a more 'finish-like" surface  (based on my reading/research... haven't done that personally).  Since the peel-ply doesn't stay on the part, it won't count towards Challenge budget.

for something more like "wing"/"foil" panels and vacuum bagging... if you do them in composites... a maybe cheaper option, especially since you can reuse it if you're careful... is to find some thicker mylar.  Cut two pieces of mylar, one to cover the top and the other to cover the bottom; and tape them together with two layers of packing tape sticking together (i.e. so only the slick tape side is seen) in the front with a ~1/4" gap between the mylar pieces being bridged by the tape.  Do you layup, slide the foil nose first into the the form and stick the whole thing in the bag.  The mylar should conform to the core/layup and provide a very even surface to the upper layer of cured resin as it's pulled out with the breather cloth and the pressure.

 

re: Carbon Fiber fender parts
I'd be a little leery of doing parts that could have rocks thrown up into them that are "pure" carbon.  It's just way too brittle to survive impacts from debris (it can't take any shear loads).  Carbon-Kevlar, maybe.  But, a better half-step would be to pick up some 1-inch carbon uni-directional "tape" and using that kind of like 'arched' reinforcement.  Like you could have run a strip along the bottom, and then fanned out from the bottom up to the central section... ala:

I'd just suggest that the carbon avoid anywhere there's going to be a hole (again with the shear loads).

nocones
nocones PowerDork
7/7/22 10:08 a.m.

These are great tips on Fiberglass.  I'll revisit them when I make more parts.  I will probably start a stand alone Fiberglass thread when I make the next round of parts.  I will be making a roof so there will for sure be more.  

nocones
nocones PowerDork
7/7/22 11:01 a.m.

Last night was all about trying to clean up the front of the fenders (as much as possible in the time I have now).

I added a flange along the bottom of the front of the fender and also along the outboard of where the cape is.   I'm really loving the shrinker / stretcher set.  I was able to bend the Flanged parts to fit 2 dimensional curvature, and get a pretty tight radius on the shrink for the bottom of the fender.  

It's not perfect and may need to get redone but it is way better then the fenders alone where.  

I also sprayed a quick coat of paint on the fiberglass parts just to see how bad they look.  They are ok.  They obviously need a skim coat of Bondo before being "finished" but they are fine for the near future.  

And just because it's fun.  View out with painted inner fenders. 

2GRX7
2GRX7 Reader
7/7/22 12:43 p.m.

Soo glad you decided to use composites! If you're looking for a, "smoother" finish, consider woven fiberglass for your final layer. I like it because it gives a carbon fiber-like pattern to the presenting side of the part. 

nocones
nocones PowerDork
7/10/22 2:25 p.m.

Ok I will update some more details but the last 2 days have been a whole mood. 

I'll just post these glamor shots for now from SubieFest. 

This is legit the first time I have seen it fully assembled from more then 5' away.  

Response has been great at the show and dozens of people are now convinced that all $2000 challenge builds are like this.  

Shamefully a non zero number of people where confused about how my beetle was let into the all Subaru car show...

preach (dudeist priest)
preach (dudeist priest) Dork
7/10/22 2:35 p.m.

Wow!!!

So fantastic, like unbelievably so.

I thought of you today at C&C:

maschinenbau
maschinenbau UberDork
7/10/22 3:17 p.m.

Holy E36 M3 dude. Being painted one color really ties the 'roo together.

java230
java230 PowerDork
7/10/22 4:00 p.m.

Holy crap does paint change it! Looks amazing. 

David_H
David_H New Reader
7/10/22 7:04 p.m.

Coolest subie I've ever seen, I love the frunk latch too, hope you derive many years of enjoyment from it

Pete Gossett (Forum Supporter)
Pete Gossett (Forum Supporter) MegaDork
7/10/22 9:28 p.m.

In reply to nocones :

It looks like you should be running it up Pikes Peak next year. surprise

Gammaboy
Gammaboy New Reader
7/11/22 9:15 a.m.

Just saw the Blipshift guys post a pic of it on Insta, realised I hadn't been back to look for a while...

Dusterbd13-michael
Dusterbd13-michael MegaDork
7/11/22 9:18 a.m.

My God. Its truly the render come to life. 

nocones
nocones PowerDork
7/11/22 10:10 a.m.

In reply to Gammaboy :

That's awesome!  Got a link?

I'm not good at searching the socials.  I expect it to show up all over the place so if you guys see it post some links

Bucky Lasek was there signing autographs doing his Subaru ambassador thing and hooning his Buckit GC8.  He came over and spent about 20 minutes looking at the car and chatting.  He thought it was the coolest car at the show.  He filmed the car for his YouTube and posted an Instagram Story on it.  He was really impressed when he helped pull the body off the car.  He was also the only person during the car show to ask to sit in it so if course I let him.

Pretty cool stuff.  It's very rewarding to have the effort result in something great.  Like always I just hope that the build can inspire people to question what they are capable of and what they really need to have to build something cool. 

NY Nick
NY Nick Dork
7/11/22 10:43 a.m.

Another awesome chapter in this build. I thought it was funny that the inner fenders were blue and then boom the whole car is painted, you are a sly one Mr. nocones!

AWSX1686 (Forum Supporter)
AWSX1686 (Forum Supporter) UltraDork
7/11/22 11:18 a.m.

Soo good!

Andy Neuman
Andy Neuman SuperDork
7/11/22 12:46 p.m.

Boy that escalated quickly. Looks great

Gammaboy
Gammaboy New Reader
7/11/22 1:11 p.m.
nocones said:

In reply to Gammaboy :

That's awesome!  Got a link?

They posted as a story, so not sure how long the link will live, but I did screen cap it

https://instagram.com/stories/blipshift/2879515382534189321?utm_source=ig_story_item_share&igshid=MDJmNzVkMjY=

 

karplus2
karplus2 Reader
7/11/22 8:11 p.m.
Gammaboy said:
nocones said:

In reply to Gammaboy :

That's awesome!  Got a link?

They posted as a story, so not sure how long the link will live, but I did screen cap it

https://instagram.com/stories/blipshift/2879515382534189321?utm_source=ig_story_item_share&igshid=MDJmNzVkMjY=

 

They didn't look close enough. There's a surprisingly huge amount of Subaru still.

nocones
nocones PowerDork
7/11/22 10:30 p.m.

Thanks for all the compliments guys.  I've been overwhelmed by the response to the car.  Feedback on the car has been positive and big.

Grimmspeed put it up on their SubieFest coverage and took a really good picture of it.  

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

A post shared by GrimmSpeed (@grimmspeed)

 

I still see everything wrong and everything left to do but seeing it through other people's lense the enormity of the achievement is starting to sink in.   Can't wait to take it over the finish line for October this year.  

Teh E36 M3
Teh E36 M3 UltraDork
7/11/22 10:54 p.m.

This is still so cool. I'm glad the world is getting to see it. 

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