Author Topic: Is it possible to have a die cast aluminum pan welded? (Read 1461 times)

kenneth cook · « **on:** August 23, 2009, 03:34:39 PM »

I have a pan that has the holes drilled through and also in the incorrect spot for the engine I want to use. I wondered if these could be welded and redrilled. I wasn't sure if it could be welded and also if the weld is now harder than the material itself. Any suggestions would be gladly considered. Ken

dssit · « **Reply #1 on:** August 23, 2009, 04:18:17 PM »

forget welding. some pans are sand cast with low grade aluminium unlike tatone pans. the best thing I found is devcon alumium epoxy putty. real strong stuff. i have been tempted to fix grandmoms dentures with it thats how good it is. my wife gave her the money to go to the dentist so that killed that.

dssit · « **Reply #2 on:** August 23, 2009, 04:31:25 PM »

i don't think welding die cast is a good idea. they crack easy enough with out adding stress from welding.

don Burke · « **Reply #3 on:** August 23, 2009, 06:36:54 PM »

All in all a bad idea to weld cast aluminum. The bad thing about welding alum, or magnesium for that matter, is that the material in and near the weld comes out dead soft, AKA temper zero Also you end up with stress risers at the boundary between the original material and the weld.
Can't say that it can't be done.

kenneth cook · « **Reply #4 on:** August 23, 2009, 07:00:44 PM »

The consensus says its a bad idea. I would think this isn't the first time one of these pans were in need of repair. There is surely not enough material surrounding the hole for a heli-coil. The only other option I thought of is to find a piece of aluminum rod that could be friction fit into the pan maybe using Jb weld to assist it then redrilled. I do have another engine but I think its hole pattern may be a bit too close to the existing ones there. Ken

john e. holliday · « **Reply #5 on:** August 23, 2009, 07:15:11 PM »

Check at your local auto parts store or high performance auto racing store. There is a metal filled epoxy that would probably do the trick on your pan. They claim they use it to fill up stud bolt holes that have been stripped. Then redrill and tap. DOC Holliday

Joey Mathison 9806 · « **Reply #6 on:** August 23, 2009, 08:09:13 PM »

what pan are you speaking of brand and class please.

dssit · « **Reply #7 on:** August 24, 2009, 07:17:01 AM »

I do non't advise trying to fix an f2a or something larger.I have repaired 1/2a and older a pans with aluminium screws and devcon putty that really worked out well. I have played with jb and decon and devcon to me is far the best. only my opinion let's hear from the pros.

kenneth cook · « **Reply #8 on:** August 24, 2009, 02:41:51 PM »

The pan is a Tatone B size . I just didn't want to discard it. I have an engine that fits the existing holes but one of the holes has been stripped out. Ken

Marvin Denny · « **Reply #9 on:** August 24, 2009, 03:21:56 PM »

Is there enough metal around the stripped out hole to install a Heli-Coil? If the old hole was a 4-40 size and stripped out, you could get a 4-40 helicoil tap and rethread it to take a 4-40 helicoil and be right back to a 4-40 screw size.

Bigiron

Joey Mathison 9806 · « **Reply #10 on:** August 24, 2009, 05:34:02 PM »

ken sorry i have a new undrilled tatone a pan but in the b size only have the harters. do as marvin said heli-coil

kenneth cook · « **Reply #11 on:** August 24, 2009, 06:21:51 PM »

I'm not sure how long the heli-coil is for starters. The other problem I believe is the fact that the pan is convex. I believe the heli-coil would protrude through the pan and for certain a good portion would have to be ground off. I guess its possible just unsightly. I just may give it a try Its not here to enter any beauty contests thats for sure. Just making an eyeball observation I have approximately 3/32 at best from the edge of hole to the edge of pan. I may be being a bit generous here in making that statement. The right leading hole is the hole in question and it has maybe a 1/16 th of material to the edge. Maybe there's a remote chance of moving the engine slightly forward or back to get into new material. Ken

Marvin Denny · « **Reply #12 on:** August 24, 2009, 07:25:07 PM »

Heli coils come in as few as three threads long, to 5 threads to as many as eight threads long. What you would have to do is tap out the pan to take the 4-40 helicoil and then get one as long as you can find and start it in. When the leading thread is at or very near the area where the hole starts to open up on the bottom (side) of the pan, stop and using a dremel cutoff wheel, cut off what remains above the pan where the engine mount rail sits. Then take a very small cone shaped abrasive bit in the dremel and carefully taper the lead-in thread at the top of the pan for easy installation of the mount screw.

Questions

Feel free to give me a call (316)838-8494

Bigiron

Dave Rolley · « **Reply #13 on:** August 24, 2009, 09:24:10 PM »

Ken,

What Marvin implied but did not state is that for small diameter fasteners you can get to the maximum recommended torque on the fastener with as little as three threads of engagement. For a 4-40 size fastener the maximum recommended torque is 12-14 in/oz. With the Heli-coil insert you will have steel on steel for the engine mounting screws which is a lot better for repeated engine removal and installation than a steel screw directly threaded in an aluminum or magnesium pan.

Dave Rolley

Double Deuce · « **Reply #14 on:** August 25, 2009, 07:41:32 AM »

You sure you have a Tatone Die Cast Pan? All the Tatone line were sand cast, the early ones from Tenzalloy, not sure re the later ones.

Double Deuce

kenneth cook · « **Reply #15 on:** August 26, 2009, 05:29:33 PM »

I was asking initially how big is the overall diameter of the heli-coil. I only have at best 3/32 of material on the outside of the hole before its out of the pan. One of the holes is slightly off center and maybe has a 1/16th. I don't know what the required drill size is so therefore I can't say for sure if it will work or not. What it sounds like is that I now have a tear dropped shaped door stop. I wouldn't want to take a chance of something coming loose damaging the engine or me. The existing holes have already caused the material of the pan to slightly bulge so I surely think anything larger in any of the holes is going to weaken it further. I did explore the option of the Devcon aluminum epoxy and its not cost effective for the small amount I need. I could surely buy a new pan for the cost . Ken

W.D. Roland · « **Reply #16 on:** August 27, 2009, 08:10:43 AM »

What brand pan?(may have missed that)
I have a pile of new and used of various size and brand--a few I will not part with but the others----

Engineering rule of thumb for threaded length engagement is bolt diameter.

We/Me/I do have formula car castings in aluminum and magnesium welded for repairs.
There are the problems others have posted and constant inspection of repair is required.
The trick is to find that special welder(not me!)
Mine is at a large local industrial fabrication facility.
His welds have less porosity than the castings!

Regular JB weld allowed to cure for a week or so should thread properly and hold if you are careful.
The 24hr cure has about 2X the strength of the quick cure stuff.

Possible you can counter bore the bottom side and insert an allen head bolt and then grind flush and use as a stud?

David
51336

don Burke · « **Reply #17 on:** August 27, 2009, 11:49:03 AM »

from this web site:

http://www.carbidedepot.com/formulas-tap-helicoil.htmTap Chart - Helicoil Threads

Tap size Drill size
2-56 3/32
3-48 #33
4-40 #31
4-48 #30
5-40 #30
6-32 #25
6-40 #26
8-32 #17

Graham Collins · « **Reply #18 on:** September 01, 2009, 10:44:59 AM »

Why not just re tap the hole to 5-40 size? Might mean a slight enlargement of the hole in the mounting lug on the engine.

And if you are fussy, you could probably retap all the holes to 5-40.

cheers, Graham in Ottawa Canada

don Burke · « **Reply #19 on:** September 01, 2009, 11:56:04 AM »

The problem I see with just tapping to 5-40 is that you will NOT have full thread depth, and the screw will probably strip out again. Tap drill size for a 5-40 is .101, body diameter for a 4-40 is .116. The stripped hole will all ready be way oversize for the 5-40 thread. Heli-coil is the best way to go.

Graham Collins · « **Reply #20 on:** September 03, 2009, 05:21:37 PM »

Good point. Really depends on badly stripped the hole is. I have re-tapped holes 5-40 that where 4-40 and somewhat stripped.

Another option would be M3.5, tap drill size is .114 or there abouts - fairly common but depends on where you live, I can get this size locally. A helicoil while it would probably work just seems to be a lot of work when there might be simpler option.

cheers, Graham in Ottawa Canada

Lyle Spiegel · « **Reply #21 on:** September 11, 2009, 03:38:52 PM »

I'm a metallurgist- specialty is welding- cast aluminum can be near impossible to weld- but if you have no choice but to try- I would contact Scott Dinger in Simi Valley, CA- he is a master welder - produces custom tube mufflers for stunt engines- and would be the only person I know who could een attempt to make your weld repair- I would suggest making a small "melt pool" in a region of the pan where there is not ant load bearing surface and see if the particular alloy can weld without cracking.
contact info:
All Weld
1367 Patricia Ave
Simi Valley, CA 93065-2812
(805) 526-9074

David Shad · « **Reply #22 on:** February 24, 2010, 08:19:06 AM »

Being a 35 year A&P and an aircraft welder the two best options I see here are
one...helicoil...as stated a three thread grab will allow the proper torgue. Then
the stud option would be next best...welding cast material that is so thin will
just not get it done. After that fill the hole with Devcon or JB weld slow cure
and an aluminum screw and let it cure well...days or even a week. Redrill and
you should be good to go.