Belly Pan

[Rick Iverson]

Gents:

I was advised by RP to anodize my 6061-6 belly pan.

[Lotus7]

Several good reasons to anodize 6061, but on a belly pan, subjected to the abuse they take, and their replacement frequency, perhaps not good value? YMMV

[SteveG]

I was advised by RP to anodize my 6061-6 belly pan.

I believe that RP's rational for anodizing 6061-T6 belly pans is 6061 starts oxidizing immediately upon manufacture. You have to remove the oxidization before applying epoxy to achieve the best bond but the oxidation process starts immediately after removing it so it is impossible to get the excellent epoxy bond because of oxidization.
Most epoxies bond to anodized aluminum. So anodize = no oxidization = excellent epoxy bond.

Ta Da
Steve

[teamwisconsin]

It looks totally bitchin. Your floorpan is gonna be on there awhile, might as well make it look killer. DB1, Crossle 45, and RF97k.

[Richard Hybels]

I’m guessing that is Richard Pare? He knows a thing of two as does Team Wisconsin.

Gents:

I was advised by RP to anodize my 6061-6 belly pan.

[tlracer]

I believe that RP's rational for anodizing 6061-T6 belly pans is 6061 starts oxidizing immediately upon manufacture. You have to remove the oxidization before applying epoxy to achieve the best bond but the oxidation process starts immediately after removing it so it is impossible to get the excellent epoxy bond because of oxidization.
Most epoxies bond to anodized aluminum. So anodize = no oxidization = excellent epoxy bond.

Ta Da
Steve

Even though anodizing is a thicker oxidation layer, perversely it helps adhesive bonding as it creates a micro-rough surface due to its porosity.

[Joefisherff]

Ethan this looks like hard anodizing versus standard anodizing would that be correct? Beautiful craftsmanship!

[jtaphorn]

Ethan, Where are the purple rivets? I assumed that was your signature style. Beautiful work that we have come to expect from you.

[teamwisconsin]

Ethan this looks like hard anodizing versus standard anodizing would that be correct? Beautiful craftsmanship!

Nope, just regular type 2 anodizing. Any anodizing shop can do it in a variety of colors. You just need to tell them the alloy you’re giving them and what color you want it. I also scuff up the areas that will get glue BEFORE it goes to anodizing. And thanks! We try hard to make them look good and go fast in equal parts!

[R. Pare]

Yes, scuff the bonding area. Doing it adds "tooth" ( surface area) to the bond.

The only problem with scuffing after anodizing the surface is that you can remove the sealer that seals the color liquid inside the anodizing crystals that are hollow and hexagonal in shape - the dye goes into the hollows and gets sealed in. I have no proof, but I would think that that could reduce the bonding strength - which is in part why I recommend only clear anodiding ( no color dye).

The other benefit of anodizing the pan is that it keeps you from getting aluminium oxide smudges on your drivers suit.

[Charles Warner]

Ethan, Where are the purple rivets? I assumed that was your signature style. Beautiful work that we have come to expect from you.

Aircraft General Standard (AGS) specs. British system from the 1920s and still used today..

Purple (Violet) rivets - L86 aluminium alloy
Green rivets - L58 aluminium alloy
Plain rivets - L37 aluminium alloy
Black rivets - l36 aluminium alloy

[Ejonzer]

Gents:

I was advised by RP to anodize my 6061-6 belly pan.

Do people still use stainless steel belly pans? I thought years ago, that was the hot thing.

[DaveW]

Do people still use stainless steel belly pans? I thought years ago, that was the hot thing.

I have a 1/8" mild steel plate under my 0.090 6061-T6 BP. It serves as protection for the aluminum BP and adds 28# of ballast.

A SS pan might be good if you want that much extra weight. I don't know how well epoxy would bond to it.

[DSR3]

7075, Type II Class 1 (un-dyed)

[Rick Iverson]

I’m guessing that is Richard Pare? He knows a thing of two as does Team Wisconsin.

Yep

Yes, scuff the bonding area. Doing it adds "tooth" ( surface area) to the bond.

The only problem with scuffing after anodizing the surface is that you can remove the sealer that seals the color liquid inside the anodizing crystals that are hollow and hexagonal in shape - the dye goes into the hollows and gets sealed in. I have no proof, but I would think that that could reduce the bonding strength - which is in part why I recommend only clear anodiding ( no color dye).

The other benefit of anodizing the pan is that it keeps you from getting aluminium oxide smudges on your drivers suit.

RP, forgot to mention the scuffing as you advised.

[Lotus7]

Geez, you guys are putting a lot of money into what we call a sacrificial part

You should see our belly pans after only a few events (curbs are fast)

[bassracer]

I anodized my last car's pan and was originally planning to do this one but ran out of time, and money for the local supplier. Bad planning. I ended up attempting to do the Alodine conversion coating but honestly, not sure it did anything for a DIY dilution/process.


I had a lot of rivets. This sucker better last.

[R. Pare]

Geez, you guys are putting a lot of money into what we call a sacrificial part

Belly pans, when installed correctly, are a large part of the chassis stiffness.

[jrh3]

I anodized my last car's pan and was originally planning to do this one but ran out of time, and money for the local supplier. Bad planning. I ended up attempting to do the Alodine conversion coating but honestly, not sure it did anything for a DIY dilution/process.


I had a lot of rivets. This sucker better last.

I think I would have done the whole pan but I’m an aircraft guy and like the appearance.

[Ejonzer]

I have a 1/8" mild steel plate under my 0.090 6061-T6 BP. It serves as protection for the aluminum BP and adds 28# of ballast.

A SS pan might be good if you want that much extra weight. I don't know how well epoxy would bond to it.

I just weighed the two floor pans, Aluminum=6lbs. SS=14lbs. Do you think it's a mistake to put a SS pan on an old Merlyn Mk20? I'm okay with the extra weight, after all, it's low.

[Art Smith]

picture below shows the "rivet check" on the 0.090" 7075-T6 type III full length belly pan for my RF-00; took four people with air driven rivet pullers to get the job done before the epoxy cooked off. cool evenings in the summer in the desert are still warm.......

Art
artesmith@earthlink.net

[bassracer]

Art. I no longer feel I have too many rivets.

[Rick Iverson]

Delete

[Rick Iverson]

Ok, that made me laugh

Art. I no longer feel I have too many rivets.

[Rick Iverson]

Chaz:

I bought the standard CS rivets from Hanson in CA. Is the a reason for the colors other than aesthetics?

Aircraft General Standard (AGS) specs. British system from the 1920s and still used today..

Purple (Violet) rivets - L86 aluminium alloy
Green rivets - L58 aluminium alloy
Plain rivets - L37 aluminium alloy
Black rivets - l36 aluminium alloy

[BeerBudgetRacing]

Chaz:

I bought the standard CS rivets from Hanson in CA. Is the a reason for the colors other than aesthetics?

To distinguish what type of rivet it is - per the chart. Builders would know based on the color.

[Bubbagsj]

It looks totally bitchin. Your floorpan is gonna be on there awhile, might as well make it look killer. DB1, Crossle 45, and RF97k.

And hope that no one ever gets to see it!!!!!!!

[Rick Iverson]

Good stuff here. Thx Bud, Happy New Year

To distinguish what type of rivet it is - per the chart. Builders would know based on the color.

[S Lathrop]

Couple things I have learned over the decades I have been attaching belly pans to tube frames is that the glue is just as important as the rivets you use. And solid rivets are way stronger than blind/pop rivets.

One person mentioned stainless rivets. I don't like them because the rivets do not do a good job of expanding and filling the hole and they tend to bend under repeated stressing and become loose. And a loose stainless rivet is close to impossible to drill out.

I have had good success with https://www.wicksaircraft.com/shop/avex-rivet/ . These are my choice for blind rivets.

I have been adding rivet strips to the inside of all the lower frame rails so I have a 2 inch wide surface to rivet and bond the belly pan to the frame. I also stagger the rivet lines 1/4 inch either side of the center line of the tubes or 1" wide strips. I have a rivet every 3/4 inch for each line of rivets.

I have done a lot of torsion testing of my frames and the process I have outlined above gives the best results and the belly pans have held up for several years of racing.