Kamai bumper repair

[SplitDash]

I got this original kamai bumper for little money.

Anyway, it needs a few repairs around the mounting holes.

Any tips for doing this ?

I didn't want to add any thickness to the mounting flange but I don't think I'll have much choice 

 

Thanks

 

 

[OldRoller]

Cut the old flange off flush with top edge of the 'bumper', position it in place on the valance and check fit and trim as necessary. Once happy, coat the valance with release agent (wax or other). Clamp and secure the dam in place and fiberglass a new flange under the upper lip and down the valance, about 2-3 inches down to ensure the curve and angle of the dam to valance. To make this part of the job easier, prepare the cloth, wet it down and place it on the underside of the dam with the valance inches extending. With help, place the dam up to the valance and reach up (a roller will help) and smooth the glass to the valance.

Let it cure, remove dam and trim/sand edges of the new flange and reinforce it with more cloth/glass. 

For install. place the dam and mark the valance at upper edge, remove dam and drill the valance for fasteners. Replace dam, mark the new flange for holes and drill flange. Final install and use stainless bolts/washers/nuts. 

A bit of work, but will allow you to seal and fair the dam to the valance seamlessly for a very professional look. Supports from the bottom edge back to the lower edge of the valance are suggested for rigidity.

Edited January 5 by OldRoller

[SplitDash]

@OldRoller Thats a great idea🤙 and one I hadnt thought of!

 

I have a brand new nose cone for my car so I could do the fitup & glass on the bench,

[OldRoller]

That would definitely make it easier!

 

[visionaut]

Simplest solution — don’t use the old mounting holes, make new ones in the good areas in between. Then just do a non-structural fill-in of the missing chunks…or run edging trim over that whole edge deep/long enough cover up the missing bits..

 

Pierre’s replica of the Kamei has an extended and reinforced mounting edge, as tear-through was a common fault with the small Kamei edge.

Edited January 5 by visionaut
Or…

[Son of Marty]

Old Roller, Is fiberglass OK to use on ABS plastic? In the past I have used a strip of 1/16 aluminum cut to the flange height to sandwich the flange to the car painted black it looked fine. 

[OldRoller]

I assumed your Kamei was fiberglass... the Pierre rep that I got was, I guess originals were ABS. If you use fiberlass cloth, saturate it with Epoxy resin (like West System) not polyester resin, and increase the coverage under the lip. Thoroughly clean the underside. 

Another method I have used on ABS is to make a slurry of ABS and acetone (small pieces soaked in about 150 ml of acetone in a sealed bottle until it melts) and spread it...but I have only done small repairs like this. 

Perhaps a better and less messy fix is to use aluminum L angle, riveted to the underside lip. You may have to use small sections (or split the horizontal  edge and bend) to match the curvature of the valance. I would probably use this method with flat rivets to make the fairing of the joint easier and it would hold up better long term than epoxy or ABS slurry. Mechanical bond vs chemical!

[Son of Marty]

Thank you kind sir, learned something new today.

[OldRoller]

😁 Glad I could pass on some knowledge gleaned by many years of total screw-ups! In the course of decades in the marine and auto field I have been forced to glue screw bang bond hammer attach frivolously many components and items of wide definition in use and importance. Some have failed miserably. Others have stood the test over many years. I think most successes included a large dose of luck... but all failures resulted in lessons learned. 

We are a tenacious sort. Nothing incites necessity of action like failure.

[SplitDash]

More good ideas there @OldRoller.

I'm leaning towards the aluminium L profile.

6/8 of them combined with some longer brackets on the bottom should make for a solid fixing.

I think I'll use SS rivnuts .

Of course I'll update here when I do the job. It's a little ways down the list !

 

Thanks again 

[SplitDash]

Well its been a while but I finally got around to this so I thought I'd update 😆.

I decided to keep it simple and go with fiberglass (i've never used it before....)

 

I located the bumper and clamped it at the fenders. The plastic at the ends is much thicker than across the front and was in almost perfect condition.

 

Once I had it located I cut the lip off with a multitool.
 

 

Then I just went for it!

around 4 layers of fiberglass mat, I brought it right out to the edge so I could lose the extra thickness in the curve.

 

 

I popped right off the body and I marked it up for cutting,

 

 

 

After the cut and a quick sand.

 

 

 

Finally mounted it up with rivinuts.

I'll get some nice countersink washers and a rubber strip once its filled and painted.

 

 

 

Only thing I would have done differently is cover the nose panel in masking tape.

While the glass mat came straight off there was some residue left that was a pain to get off!

 

I also made two brackets to support the lower edge, just like it originally had 

Edited August 22 by SplitDash

[OldRoller]

Nice work, well done. Brush a couple coats of unthinned epoxy on the top, will make fairing the repaired area easier.

Gonna look good! 

[chargin]

Also, add some metal struts below, originally they had them

 

really helps rigidity 

 

[Einspritz]

You might consider using a 1/2" x 1/8" aluminum strip to sandwich the flange to the body.

 

And you can epoxy fiberglass a 1.5" abs pipe behind the opening to provide a means for ducting air to the brakes....

 

It's only lasted 350,000 miles....

 

Do make struts to the body! And beware of sharp inclines.