Cracked Trailer frame repair ideas

Truck and Trailer discussion
DMc-1
Posts: 8
Joined: Sun Sep 29, 2019 6:00 pm

Re: Cracked Trailer frame repair ideas

#26

Post by DMc-1 » Sun Sep 29, 2019 6:38 pm

This is the result of a simple longitudinal crack in the web. I just noticed my friends trailer has started failing in the same manner however his boat is a Carolina Skiff.

DMc-1
Posts: 8
Joined: Sun Sep 29, 2019 6:00 pm

Re: Cracked Trailer frame repair ideas

#27

Post by DMc-1 » Sun Sep 29, 2019 6:45 pm

Pics of trailer I beam failure and boat rigging.
Attachments
1EA6028C-B9E1-4ED9-97ED-A3F21381E0ED.jpeg
1EA6028C-B9E1-4ED9-97ED-A3F21381E0ED.jpeg (168.26 KiB) Viewed 1219 times
03030C68-B59D-4BF0-A66D-EB9F4A191C90.jpeg
03030C68-B59D-4BF0-A66D-EB9F4A191C90.jpeg (92.74 KiB) Viewed 1219 times

DMc-1
Posts: 8
Joined: Sun Sep 29, 2019 6:00 pm

Re: Cracked Trailer frame repair ideas

#28

Post by DMc-1 » Sun Sep 29, 2019 6:47 pm

Failed area.
Attachments
B7EA645E-54C4-4D37-8839-A9CAAE059152.jpeg
B7EA645E-54C4-4D37-8839-A9CAAE059152.jpeg (120.92 KiB) Viewed 1219 times

DMc-1
Posts: 8
Joined: Sun Sep 29, 2019 6:00 pm

Re: Cracked Trailer frame repair ideas

#29

Post by DMc-1 » Sun Sep 29, 2019 6:50 pm

[attachment=8]F380AB41-B1B4-40BE-8C00-546142280E5B.jpeg[/attaAll photos

Please help me make the appropriate repairs. Thank you.
Attachments
575A5776-D3EE-4229-8789-07AE9062BC4F.jpeg
575A5776-D3EE-4229-8789-07AE9062BC4F.jpeg (168.26 KiB) Viewed 1219 times
F380AB41-B1B4-40BE-8C00-546142280E5B.jpeg
F380AB41-B1B4-40BE-8C00-546142280E5B.jpeg (92.74 KiB) Viewed 1219 times
B6FA49A0-515F-4929-B658-218B3D15DAE5.jpeg
B6FA49A0-515F-4929-B658-218B3D15DAE5.jpeg (87.29 KiB) Viewed 1219 times
7440593F-FA81-49DD-9911-90E7B67C6B76.jpeg
7440593F-FA81-49DD-9911-90E7B67C6B76.jpeg (120.92 KiB) Viewed 1219 times
B4F5ED50-1349-42EB-A04A-56FD81A920DD.jpeg
B4F5ED50-1349-42EB-A04A-56FD81A920DD.jpeg (128.89 KiB) Viewed 1219 times
162BE111-ED8F-4F35-89D2-52859C4F19FE.jpeg
162BE111-ED8F-4F35-89D2-52859C4F19FE.jpeg (134.73 KiB) Viewed 1219 times
52EDFF92-217F-4C8D-A7EB-F9582BFB6CF2.jpeg
52EDFF92-217F-4C8D-A7EB-F9582BFB6CF2.jpeg (116.17 KiB) Viewed 1219 times
6D6734A2-7431-49D4-878A-E7DA99AC3EE1.jpeg
6D6734A2-7431-49D4-878A-E7DA99AC3EE1.jpeg (136.91 KiB) Viewed 1219 times
6822B707-0715-4618-9E21-9851F42C05AB.jpeg
6822B707-0715-4618-9E21-9851F42C05AB.jpeg (125.88 KiB) Viewed 1219 times
8D361829-0BB0-4F6F-B23E-4B76DF8A50F0.jpeg
8D361829-0BB0-4F6F-B23E-4B76DF8A50F0.jpeg (149.99 KiB) Viewed 1219 times

kmorin
Donator 08, 09, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19
Posts: 1475
Joined: Mon Aug 18, 2008 1:37 am
Location: Kenai, Alaska

Re: Cracked Trailer frame repair ideas

#30

Post by kmorin » Mon Sep 30, 2019 2:49 am

DMc-1, not sure without lots more photos if I can understand the exact cause of the lower I/H beam flange failure? but I think this will cure the problem.

#1 remove all loads on the lower flange= get off the cross piece holding the side landing or loading guides.
#2 Get all the lower flange failed parts out of the way - cut , grind, plaz : remove the cracked out and em-brittled lower flange pieces.
#3 cut "back" forward of the forward crack and failure point and aft the after break line and failure points, by about 1/2" to 3/4" inch and these cuts will go across (right angles to beam flange) the entire lower flange of the I/H beam of the trailer's rail.
#4 fit a replacement piece of plate the same size as the flange- don't worry about any ASME taper, just use a flat bar of the same main thickness and width.
#4A bevel the forward and after ends of the beam's flanges where they are cut, bevel the replacement flange plate/bar/piece of equal cross section aluminum.
#4B the bevels can be even top and bottom, or all top or all bottom depending on the welding skill, welding power supply type and the welding process used (MIG VS TIG)
#4C bevel the bottom of the beam's web. This will remove the previous weld along the failed sections and will taper both sides of the web's lower edge where the new/replacement flange piece will butt (top fillet) to the lower edge of the existing I/H beam's web. This will be a horizontal weld- the bevel will allow a recessed fillet on both sides, the bevel will reduce the cooling contraction distortion of the flange when welded to the web.
#5 replace all the lower flange pieces removed as damaged/cracked/broken pieces by welding along the two butt welds to the existing remaining flange ends and the web's lower edge.

#6 fit another piece of plate to the flange = equal or thicker in vertical section wider by 1/2" than the flange replacement piece used to replace the lower flange removed by cutting out the broken pieces plus a 1/2 or 3/4" length.
#6A the added piece of lower flange or 'doubler' will be 6" longer that the replaced pieces of the lower flange. This piece will extend 3" fore and aft the butt joint of the flange replacement bar.

#7 drill the Ubolt holes to fit the bolts.

#8 the beam needs to be boxed-fish plated- reinforced from top flange to bottom
#8A fit a pair of vertical plates of 1/2 the thickness of the beam's web that fit from the lower edge of the upper flange to the upper edge to the top of the doubler beneath the replacement lower flange- this will cover the edge of the newly added lower flange replacement bar. The boxing plates will be as long as the lower doubler- 6" longer than failed area that is removed.
#8B this plate needs to be beveled along its lower, outside edge- the upper edge fit forms a natural fillet and will be continuously welded along its length with the upper flange edge.
#8C by beveling the lower edge of the 'boxing plates' and the fit sitting on top of the wider, lower flange doubler- the weld of the boxing plates will be and outside V fillet in the horizontal.
#8C before fitting the boxing plate for welding, hole saw wrench end openings so you can tighten the nuts onto the Ubolts holding the cross pieces under the trailer.

cut out the cracked material wider than the cracked material both fore and aft,
bevel the cut ends to weld the new bottom flange cut to fit into the lost lower flange
prepare a lower flange doubler longer than the replaced lower flange; drill to fit bolts
box the I beam from top flange to lower doubler- boxing plates are thinner than web but parallel to web
make sure you can get to the bolts before installing doublers!

Cheers,
Kevin Morin
Kenai, AK
kmorin

kmorin
Donator 08, 09, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19
Posts: 1475
Joined: Mon Aug 18, 2008 1:37 am
Location: Kenai, Alaska

Re: Cracked Trailer frame repair ideas

#31

Post by kmorin » Mon Sep 30, 2019 8:44 pm

DMc-1, after looking at the welds in the failure points I'd remark some more.

The welds don't seem to have much fusion- they're cold lapped in many places. This implies the outside of some of the welds look OK but... in fact their lower root faces- on the web seem to have given up WAY to easily.

With that said, I can't see enough detail to make this pronoucment/condemnation of the beads without more focused and close up root face failure pictures. So... it possible there was a weld alloy problem? and also there's a potential the weld areas were beyond the wattage/welding amperage & voltage needed fro this work?

I'd have said a 300 A power supply was minimum for the work shown, and because large TIG beads were carried- I'll make the assumption at least this size power supply was used? However, if the roots of the welds actually torn out- sections of the face of the flange where the welds are parted??? Can't verify visually?

THEN, the weld may not have failed but the weld to parent metal face (Root Face Bond) may have failed?

If that is the case- it would be very good to establish from the trailers' vendor(s) what alloy was I or H beam was used? I'd have assumed 6061-T6 but since my assumption my be totally wrong? It would be good to confirm? NEXT... if the beam was 6061 and welded with 4043 or 4093 filler????

"Well there's your problem!" The filler must be 5356 with no 40series filler being used in the application.

Next, due the failure of the flange bolt loading I'd say the uprights are the cause of this failure. They may 'sing' or vibrate on the highway ? If they do? (and I'd guess they did?) THEN the vibration would be 'seen' by the trailer frame at the heads of the U-bolts - the vibration combined with the stress load of the U-bolt hole would be enough to create a high frequency oscillation at the point you show flange failure.

To dampen the uprights' "whistling in the wind"- put a truck strap forward or aft from the tip down the frame - this will dampen the forward and back vibration of the plastic pipe covered square stock used a landing guides.

Something has been vibrating this U-bolt hole - A "HOLE" BUNCH!! I think the weld failures came after the flange cracked across, and weld to flange separations are extensions of the original failure on both sides of the bolt holes?

A little tension, along the axis of the frame beams on the uprights will seriously reduce this wind oscillation due to highway speed travels.

Just another note to help your consideration of repairs.

Cheers,
Kevin Morin
Kenai, AK
kmorin

DMc-1
Posts: 8
Joined: Sun Sep 29, 2019 6:00 pm

Re: Cracked Trailer frame repair ideas

#32

Post by DMc-1 » Fri Oct 04, 2019 8:36 am

Kevin, thank you for the detailed recommendation. The webbing is cracked/sheared completely to the top flange and the top flange has torn and only has 1.5” remaining intact. Basically the I-Beam broke in two. The trailer is rated for 6 tons and usually carries 2.5-4 tons. In studying this for some time now perhaps the issue lies with the top of the beam not being laterally braced, the load at the ramp’s crest being transferred to the front axle while the beams strain and deflect inward. Would a diagonal moment connection from the top flange webbing to the inside of the guide post carrier stop the flex at this point, and additional crossmember at the boats transom position bolted beneath the inside top flange prevent the transfer of flex forward?
Is there danger of making the trailer too rigid?

DMc-1
Posts: 8
Joined: Sun Sep 29, 2019 6:00 pm

Re: Cracked Trailer frame repair ideas

#33

Post by DMc-1 » Fri Oct 04, 2019 8:59 am

Kevin, welding the webbing alone doesn’t seem sufficient. Should I reinforce the webbing on both sides with plate the same width as the beams webbing and weld them all around before boxing? Should the existing gussets be replaced or discarded? The boxing of the beam is the same design used by Trailer Train on its low level piggy back flat cars at the draft gears. I have experience in the railcar repair and maintenance field as a level VI Class A Mechanic. All of this experience was pre aluminum some 25 years ago. I took the trailer to a shop where it was repaired before and now am considering getting the right welder and doing the repair. Which will lead me to more questions about filler, machine, mig or tig, spool gun or wire feed. I am a stick/mig welder by trade and can prep/fit rather proficiency. There are other trailers around this village which are displaying similar failure symptoms. Merely buying new trailers doesn’t solve the underlying problem. The consensus is to get a new one. My friends new one, which is under my stilt home is cracked in the same place. Anyone having any input is appreciated.

kmorin
Donator 08, 09, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19
Posts: 1475
Joined: Mon Aug 18, 2008 1:37 am
Location: Kenai, Alaska

Re: Cracked Trailer frame repair ideas

#34

Post by kmorin » Fri Oct 04, 2019 12:03 pm

DMc-1
yes if the web is fully cracked, then remove all (the vertical gussets/plates).

clamp the entire beam to some strong-back that will hold it flat,
bevel the edges of the beam's vertical tear, crack, flaw
Weld up, and sand flat and fish plate both sides with fish plates that are 3x the beam with in length.
If there are cracks at all the verticals?? then remove them all, sand and inspect the HAZ at each location- may need die penetrant to see if there are cracks as sanding often smears aluminum over a cracked area?
The fish plate of the web would be equal to one 1/2 web thickness each side - min.
The fish plate's ends need to be at least one if not 1-1/2 the web depth away from any vertical cracks and the ends rounded not pointed or squared vertically. So the fish plates' profile would be the normal 45 to 60 degree taper- but the end of the tapered ends would be rounded to keep from 'notching' the beam's web with a weld vertically oriented from flange to flange.

The boxing is part of the beam reinforcement for the load this point. Tying the flanges' outer edges together will make the entire beam act as a box not a single I/H shape in section. Therefore the load capacity goes up some what higher for the same section area.

I still think there is a highway vibration component to consider -due to the bolts showing breaking out- the embrittlement of the lower flange was caused by something- don't see how loading just the axle to beam point would make the guide posts the point of failure?

Perhaps as the load was concentrated at the top of the ramp- the beam loading was higher and this is the failure point instead of the axle to frame/beam connection? CAn't see photo of that location- but worth inspecting very closely for failure? Maybe as the beam was pulled over center the lower flange was serious compressed at the axle connection and seriously tensioned just above that connection- and the HAZ of the beam near the vertical welds was the failure point and the beam cracked top down?

I would tend to put a top flange doubler on too. This would be an added tension member to the top flange , laying on the flange with the edges one thickness inside the top flang and twice the thickness of the flange - extending from the boxed in area aft - over the axel connections area. The idea is to give the beam an added tension strip or top flange by increasing this element's section area to carry tension.

Interesting boat! bow well skiffs aren't all that common but where you have to work shallow or on the beach even- only been involved with one- a beach seine jitney for Kodiak Island fisheries.

Cheers,
Kevin Morin
Kenai, AK
kmorin

Tfitz
Donator '16
Posts: 334
Joined: Mon Jun 23, 2014 10:08 pm

Re: Cracked Trailer frame repair ideas

#35

Post by Tfitz » Fri Oct 04, 2019 2:19 pm

My method of fixing the cracked trailer frame worked out great for me. I trailered my boat from Fairbanks to Kenai to Valdez and back to Fairbanks this summer after the repair with no problems! I fact it acted like a different trailer. The boat quit bouncing on the trailer due to the stiffer tongue and took the brunt of the frost heaves in the torsion axles like its supposed to.
Attachments
20181204_200759-resized-1024.jpg
20181204_200759-resized-1024.jpg (52 KiB) Viewed 1110 times
20181203_192734-resized-1024.jpg
20181203_192734-resized-1024.jpg (77.42 KiB) Viewed 1110 times
20181204_200850-resized-1024.jpg
20181204_200850-resized-1024.jpg (40.52 KiB) Viewed 1110 times

Post Reply Previous topicNext topic