1932 Roadster - Rear Hood Hinge Bracket?

[glennpm]

Thanks hotrodA, glad to help you ahead of time.

I love the maroon color too. It is very dark out of light, but the wonderful in light or with a flash. The color is a 1969 Mercedes one pass, i.e. no clear coat.

It's DB542 (Mercedes Code). Dupont acrylic enamel 8342A.

Glenn

[glennpm]

I don't want to get off topic here but I was also talking with bullockv8 about the front Bob Drake hinge bracket. It is not an accurate reproduction either. The hole center to center spacing is wrong, too wide and has to be ground and re-drilled to get it to fit. I had an original with deteriorated plating to compare it to.

[hotrodA]

Originally Posted by glennpm

Thanks hotrodA, glad to help you ahead of time.

I love the maroon color too. It is very dark out of light, but the wonderful in light or with a flash. The color is a 1969 Mercedes one pass, i.e. no clear coat.

It's DB542 (Mercedes Code). Dupont acrylic enamel 8342A.

Glenn

Thank you!!

[glennpm]

Hi David,

I was able to get the old/repro seal out a few days ago. I also got some good pictures of an original along with a thickness measurement of 0.21" approximately from rbullockv8. Thanks Rich!

You mention keeping the rear bump in place so if so, the only way to realistically remove rubber with a grinder or sander, would be to take material off of the bottom, especially toward the front bottom corner of the seal.

I will reduce the larger thickness on the bottom toward the front. Should I leave the small raised bump on the rear, the part closet to the interior when installed? Does your original measure about 0.21" or what?

Thanks,
Glenn

Originally Posted by DavidG

I'm away from my car stuff until late next week. I can provide measurements and a photo of the cross section of it at that time. The original seal is of uniform thickness except for the raised lip on the forward edge, unlike the reproduction. Why the original was not copied is a mystery, but an old one as the faulty reproduction has been on the market for decades.

[DavidG]

Take the rear 'bump' off as it serves no useful purpose and it certainly would hinder the removal of the firewall. I gather that you no longer need a photo of an original, correct?

[glennpm]

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Hi David,

Okay I'll remove the rear hump, the one closest to the rear when installed. I'm good on pictures, thanks to rbulloock.

Could you please tell me what thickness your seal/s is please? Rich measured about 0.21"

Thanks you and appreciate the help!

[DavidG]

I measured two originals that are not yet installed back in their cars and both are 7/32", which is close enough to .21 to call them all the same as I was not using a digital caliper. The thickness is uniform over their entire width except for the bead on the engine compartment side (when installed).

[glennpm]

Excellent, thanks David!

[rbullockv8]

I actually ground away most of the upper middle hump that you label in the photo "Grind any of this away?" I don't remember working on the bottom of the seal at all, but I might have.

[glennpm]

Good thanks Rich.

First step will be to remove the small hump to the right in my pictures, the one toward the car interior. I'm then going to try to grind and sand both the top and bottom humps closest to the seal tee leg to attempt a uniform thickness of 7/32" or .201.

[32phil]

Just a side note. Don't forget to take paint "build up" into consideration, especially on the inner surfaces that are not sanded as much during the paint process. Today, with Primers/Filler Sealers and Base coat/Clear coat finishes it can build up fast. On my 32 Phaeton we couldn't put the hood hinge in because of the paint (Lacquer on that one, 20+ yrs ago) build up in the center hood hinge channel.

[glennpm]

I hear you on the paint buildup Phil.

Okay, I got a new gasket today. The rubber seems softer than the one I had in but its been a while. I'm now debating on what to grind.

- Taking off the back edge bumps top and bottom, the ones that point into the interior
- rbullock thinks he may have just ground and sanded the top to get the target thickness
- I'm thinking about removing all of the hump on the front, firewall bottom side. From my measurements, I get .21 if that hump is removed.
- Calipers are set at .21" in my last picture so you can see what I mean by removing the bottom hump.

[rbullockv8]

Pic #3 looks good!

1. The front lip (showing facing downward in your first photo) is the only part visible between the firewall and cowl, so it doesn't impact the fit. I think the main problem is the combination of the forward bottom of that lip along with the center hump. And maybe it's just the center hump that's the problem.
2. I suspect removal of the back edge bead might make it easier for you to reinstall since you are squeezing it into limited space between the firewall and cowl. Just a guess. Hope you can try it.
3. You might be right about removing the bottom hump (facing upward in the first photo) to get to .21".

However, no matter how soft the rubber is, you don't get much compression when it's spread out over the top 2.5 - 3 feet of the cowl. You just can't compress it much across an area that wide. If I get under my dash, I can see some gaps where my modified seal doesn't, well, seal. Guess I ground it too much. But I'm not going to be driving this in the rain, so I'm not worried. Many other gaps/holes in an open cab pickup.

One other thing: The right thickness for my truck might be different for your roadster. I'm sure the firewalls are the same, but the body cowls are different. Therefore, you might have a different fit and results.

Finally, isn't it amazing how some dumb thing like this takes so much time!! :-).

[glennpm]

Thanks Rich for responding again!

1. The front lip (showing facing downward in your first photo) is the only part visible between the firewall and cowl, so it doesn't impact the fit. I think the main problem is the combination of the forward bottom of that lip along with the center hump. And maybe it's just the center hump that's the problem.

Yes, agreed. I'm leaving this part of the seal as is.

2. I suspect removal of the back edge bead might make it easier for you to reinstall since you are squeezing it into limited space between the firewall and cowl. Just a guess. Hope you can try it.

Yes, even though it fits within the "0.21" envelope for the most part, removing this rear lip will make it a whole lot easier to reinsert especially along the vertical section between the cowl and firewall.

3. You might be right about removing the bottom hump (facing upward in the first photo) to get to .21".

Yes by taking off the bottom hump, I meet the thickness envelope and I can monitor better the amount of rubber I'm removing. This would be a lot tougher on the top hump. I don't have one of those fancy HF sanders like you do ;-)

However, no matter how soft the rubber is, you don't get much compression when it's spread out over the top 2.5 - 3 feet of the cowl. You just can't compress it much across an area that wide.

Yes, I know and should have left that comment off. It is still relatively hard and to get it to compress uniformly, it would probably take 100lbf.

If I get under my dash, I can see some gaps where my modified seal doesn't, well, seal. Guess I ground it too much. But I'm not going to be driving this in the rain, so I'm not worried. Many other gaps/holes in an open cab pickup.

I don't plan much rain riding either.

One other thing: The right thickness for my truck might be different for your roadster. I'm sure the firewalls are the same, but the body cowls are different. Therefore, you might have a different fit and results.

Yes

Finally, isn't it amazing how some dumb thing like this takes so much time!!

Absolutely!! When I was re-posting, I was thinking the same thoughts and also ... these guys are waiting for me to go away and give this thing up :-)

It was very hard to get out so I don't plan to do any trials on this!! Amazing that this "perfect replacement" is so not.

Glenn
:-).[/QUOTE]

[glennpm]

Okay, follow up on my too thick seal problem for the record and next guy.

I used a small electric sander with 100 grit paper and modded the rubber as I had planned above. I removed a good part of the innermost hump, the raised portion on the front bottom edge and then last; the top hump in the elbow part of the seal.

I had to go back and forth on the whole seal a number of times measuring as I trimmed. For the last part, as I was getting close to my target thickness of 0.21", I took measurements with a caliper every couple of inches, worked thicker parts and then repeated. I went back and forth the whole length three or four times until all was uniform.

Today I sprayed both surfaces of the seal with dry Teflon lube and let it dry well. I started in the middle by the brackets and worked the center in by hand. I worked along each side from there using a wood block, rubber hammer and hand prying to get it all in. The bottom of each was trimmed to fit. It went in without too much trouble. It took me maybe an hour to install the seal.

I put the hinge bracket in a little while ago and will now pull the rest the cowl down tight and see if I need to change any of the front three body to frame shims per side next. Fit is good now after sanding away about 1/8" of rubber thickness!

[DavidG]

One easy-to-overlook-until-later byproduct of an overly thick seal is that if you're using a stock instrument panel and a stock firewall, the dash light switch and throttle openings in the instrument panel will end up being below center in the oval opening in a stock dash. That's not such a big deal with most model Bs, but it may lower the hole for the choke rod on V-8s to the point that the choke rod escutcheon will not clear the top of the bottom of the stainless steel oval moulding on the inside perimeter of the oval opening.

[rbullockv8]

Nice job, glennpm! You're a craftsman compared to me. :-) And the fit of your rear hood hinge bracket looks perfect. Glad you were able to get the seal back in without much trouble.

[glennpm]

Thanks Rich! Its going better than I thought too.

[Baron]

I ran into this very same problem this afternoon and checking here found out exactly what I need to do. Thanks to all for this information.

[glennpm]

Excellent! This group is a great place for help and information.