Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
STOP!! Never post your email address in open forums. Bots can "harvest" your email! If you must share your email use a Private Message or use the 
smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
HerronScott
Darth Vader
Offline
That was my concern about the expanding foam as well (moisture absorption).
Scott
Scott
-
Hi Guest!
You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
There are some perks with a member upgrade!**Upgrade Now**
(PS: Subscribers don't see this gawd-aweful banner
The start of something big. Frame off restoration
- Thread starter justin_mercier
- Start date
Share this page
OP
justin_mercier
Jedi Warrior
Offline
Um, this stuff is waterproof, and used in cars all the time. If this stuff is as bad as everyone is saying that it is... wouldn't frame shops and custom car shops not use it? For our triumphs, Ratco offers foam filling as one of their options for water sealing the insides of their frames as well. In fact it was Tony from ratco who suggested that I get some of the expanding foam filler used for cars and then cap off the holes with little rubber plugs.
2 part urethane foam in ~2lb density would fill the cavities completely, it's closed cell so it doesn't hold moisture, and I'd be capping the holes with rubber plugs. If this stuff is so bad, why is it pretty standard to use urethane expanding foams on vehicles these days?
2 part urethane foam in ~2lb density would fill the cavities completely, it's closed cell so it doesn't hold moisture, and I'd be capping the holes with rubber plugs. If this stuff is so bad, why is it pretty standard to use urethane expanding foams on vehicles these days?
HerronScott
Darth Vader
Offline
Justin,
I did a brief search and found some interesting information on using specific types for filling chassis and body cavities as you mention which I had naver heard of before!
Scott
I did a brief search and found some interesting information on using specific types for filling chassis and body cavities as you mention which I had naver heard of before!
Scott
Fair point Justin, provide it is the right stuff, in the right application, and designed to be used from the start. We've seen lots of examples of foam that was not supposed to hold water do just that, as well as preventing circulation of air when things do get wet, which they will. How a production line of a modern car uses this isn't necessarily indicative of what a hobbyiest can do.
It is your car, do what you think is right and makes you happy...
It is your car, do what you think is right and makes you happy...
BRSLimited
Jedi Trainee
Offline
I'm thinking of personal experience with boats, I know not the same thing but the same basic principle. In my sailboat the lead weight in the keel was encapsulated in expanding foam and supposed to keep any water out that did manage to find it's way into the boat. After a few years the foam ends up breaking down and next thing you know your drilling holes in the keel to drain 50 gallons of water out. If these cars were used as daily transportation all year like they used to be it might be worth while but how many of us do that anymore?
OP
justin_mercier
Jedi Warrior
Offline
Yesterday I prepped and primed the work that I had done on the differential mounts, and this morning before work I painted them. I forgot to take photos before I got them all dirty with grinding dust from the work I was doing tonight, but I must say, they dont look that bad all things considered.
Now the frame has 3 areas that need repair to the boxed in members. The "oh crap" part from above, and a section at the rear on the very end. Tonight I prepped them for repair, trimming back to good metal and sanding down to clean metal around the edges.
Here's the part at the back. There's supposed to be a support in the middle here where one of the bolts that holds the rear bumper support goes, but it was totally rusted out, and all but gone. As you can see, the frame was previously acid dipped, but it's been such a long time that there's a little surface rust forming inside again. I'll spray everything down with that phosphoric acid rust converter & paint prep stuff, and then spray as much good paint inside to seal it again before I do my welding. Here's the rear section trimmed back to good metal.
Under the Tshirt was the other bad spot. After trimming back one side, I was able to run a vacuum all around the inside of the frame to make sure I got rid of all the loose stuff.
On this side, the top of the frame looks in just fine shape, and the sidewalls on the whole thing are in great shape.
Again, as mentioned before, there's a little surface rust on the inside, although for the most part it's clean, after the acid dipping that had been done.
The other side however has a rust hole in the top as well, although most of the metal looks good outside of that one area. The top Tshirt will be coming off and be replaced so that can be repaired as well.
Next I've got to cut out patches to fit the 3 holes I made, and get them as close to an absolute perfect fit as I can.
Now the frame has 3 areas that need repair to the boxed in members. The "oh crap" part from above, and a section at the rear on the very end. Tonight I prepped them for repair, trimming back to good metal and sanding down to clean metal around the edges.
Here's the part at the back. There's supposed to be a support in the middle here where one of the bolts that holds the rear bumper support goes, but it was totally rusted out, and all but gone. As you can see, the frame was previously acid dipped, but it's been such a long time that there's a little surface rust forming inside again. I'll spray everything down with that phosphoric acid rust converter & paint prep stuff, and then spray as much good paint inside to seal it again before I do my welding. Here's the rear section trimmed back to good metal.
Under the Tshirt was the other bad spot. After trimming back one side, I was able to run a vacuum all around the inside of the frame to make sure I got rid of all the loose stuff.
On this side, the top of the frame looks in just fine shape, and the sidewalls on the whole thing are in great shape.
Again, as mentioned before, there's a little surface rust on the inside, although for the most part it's clean, after the acid dipping that had been done.
The other side however has a rust hole in the top as well, although most of the metal looks good outside of that one area. The top Tshirt will be coming off and be replaced so that can be repaired as well.
Next I've got to cut out patches to fit the 3 holes I made, and get them as close to an absolute perfect fit as I can.
OP
justin_mercier
Jedi Warrior
Offline
My camera is really on the way out, so again photos from my iphone and nowhere near as good =/
I took to repairing the back section this evening.
First here's a photo of how it looked before i trimmed it out (post above) This is a real bad photo, but you can see it's got a ton of little holes in it and is in bad shape.
After trimming it out, I cut a repair panel as close as I possibly could with a lot of grinding on my belt grinder to get the fit exact
The magnets held it in place while i tacked the repair piece down. In so doing I realized my ground was bad, and i wasn't clean enough around the weld to get a good arc, so i stopped here and wire brushed the rest of the paint off in the back. Then i proceeded to make a bunch more tacks, and then started to connect them messily.
The individual runs of weld weren't so bad this time, it looks a lot worse in this photo than it really was
I forgot to get a photo of the next part, but I then took my flap disk and ground all the welds flush to make sure that I had full penetration, and to make the repair seamless. I had to touch up a spot here and there and re-grind them down again, but for the most part it was good. I then went and pounded away all over the panel with my pick hammer to make sure everything was nice and solid. Finally I hit it up with some self etching primer, inside and out, and I'm waiting for that to dry overnight before I put a finish coat of black on it.
I took to repairing the back section this evening.
First here's a photo of how it looked before i trimmed it out (post above) This is a real bad photo, but you can see it's got a ton of little holes in it and is in bad shape.
After trimming it out, I cut a repair panel as close as I possibly could with a lot of grinding on my belt grinder to get the fit exact
The magnets held it in place while i tacked the repair piece down. In so doing I realized my ground was bad, and i wasn't clean enough around the weld to get a good arc, so i stopped here and wire brushed the rest of the paint off in the back. Then i proceeded to make a bunch more tacks, and then started to connect them messily.
The individual runs of weld weren't so bad this time, it looks a lot worse in this photo than it really was
I forgot to get a photo of the next part, but I then took my flap disk and ground all the welds flush to make sure that I had full penetration, and to make the repair seamless. I had to touch up a spot here and there and re-grind them down again, but for the most part it was good. I then went and pounded away all over the panel with my pick hammer to make sure everything was nice and solid. Finally I hit it up with some self etching primer, inside and out, and I'm waiting for that to dry overnight before I put a finish coat of black on it.
Pictures always make the welds look worse on the forum than they do in person - drives me nuts.
Weld got through to the inside OK?
On an open section like this probably not needed, but you might want to consider weld through primer on any enclosed sections.
Did you treat the surface rust before putting the primer in?
Good progress.
Weld got through to the inside OK?
On an open section like this probably not needed, but you might want to consider weld through primer on any enclosed sections.
Did you treat the surface rust before putting the primer in?
Good progress.
Brinkerhoff
Jedi Knight
Offline
Are you sure the area on the frame where the rear suspension attaches to is not soft also ? Now is the time to fix it. I thought the guy from Ratco checked this out . Looks pretty rusty to me inside. Kevin
OP
justin_mercier
Jedi Warrior
Offline
tdskip said:
Yes, I used purple power rust treatment (phosphoric acid rust converter and paint prep) yesterday morning on all the interior surfaces that I now had access to.
The weld got through alright with good penetration. the few spots that didn't, I went back over until they did.
OP
justin_mercier
Jedi Warrior
Offline
Brinkerhoff said:
The trailing arm wings were already fully re-boxed and replaced. It's hardly any rust at all on the inside, just a light surface dusting, which i could rub off with my fingers... and probably better than anyone else's frames unless they've been recently dipped. These frames had no rust proofing of any sort on the inside from the factory. Tony said that this frame is in better shape than probably 90% of the ones under people's cars today.
OP
justin_mercier
Jedi Warrior
Offline
Here's a photo of the weldable primer that i'm using. Picked it up at a local welding supply house.
This afternoon I prepped another side for welding, and will be heading back out to prep the other side and get the patches fit exactly
This afternoon I prepped another side for welding, and will be heading back out to prep the other side and get the patches fit exactly
OP
justin_mercier
Jedi Warrior
Offline
justin_mercier said:
I may have misunderstood your question above. If you meant the frame at the point where the trailing arm attaches, it was solid there, no perforations, but more pitted and worn than I liked, so I ended up chopping out a section there that I'll be re-boxing as well, though I dont know if it really /needed/ it. You'll see the photo in my next post. Only one side was thin the other looks a little ugly from some ground down weld beads, but is still much more solid.
OP
justin_mercier
Jedi Warrior
Offline
I cut out another area that, while not perforated, didn't seem as solid as I'd like, since I only want to have to be down here welding once.
I welded in the patch, and unfortunately without my real camera working right 90% of the time, I cant get photos of my much nicer looking weld beads =P
Here's the spot welded in before grinding.
and here it is after grinding down the welds flush (I did a much better job with penetration this time, and didn't have to spend a lot of time re-welding after grinding) and priming it
I welded in the patch, and unfortunately without my real camera working right 90% of the time, I cant get photos of my much nicer looking weld beads =P
Here's the spot welded in before grinding.
and here it is after grinding down the welds flush (I did a much better job with penetration this time, and didn't have to spend a lot of time re-welding after grinding) and priming it
OP
justin_mercier
Jedi Warrior
Offline
Aaand, time to fill in that new hole that I cut.
Here's the patch shaped and tacked in place.
This is the best shot yet of some of my welds. They're messy still, but at least I'm getting that overlapping dimes type look in them so I'm moving a puddle and getting penetration. To prevent warpage, or getting an area to hot, I've been playing connect the dots with my tack welds.
After cleaning up the weld, everything is flush, the dimples you see are from my pick hammer, going over everything and listening to make sure it all sounds solid.
And lastly, re-priming this area to let it all dry so I can go over it with the top coat enamel tomorrow and be done with this side (until I get my replacement bottom tshirt from Moss motors, it's in the mail)
Here's the patch shaped and tacked in place.
This is the best shot yet of some of my welds. They're messy still, but at least I'm getting that overlapping dimes type look in them so I'm moving a puddle and getting penetration. To prevent warpage, or getting an area to hot, I've been playing connect the dots with my tack welds.
After cleaning up the weld, everything is flush, the dimples you see are from my pick hammer, going over everything and listening to make sure it all sounds solid.
And lastly, re-priming this area to let it all dry so I can go over it with the top coat enamel tomorrow and be done with this side (until I get my replacement bottom tshirt from Moss motors, it's in the mail)
OP
justin_mercier
Jedi Warrior
Offline
tdskip said:
It certainly makes the welding much easier! An extra few minutes at the belt grinder looks like it saves me 10 minutes fussing with my weld, grinding it off, re-welding where I just ground off the bad weld, etc =)