Let's get a-head here.. Fixing a broken head-hole.

PermanentSexHair · Post by **PermanentSexHair** » Thu Nov 18, 2021 9:46 pm

Ok repair experts gather around I have a fun one for you.

This doll head was mounted properly and failed in light usage. The material around the captive-nut was EXTREMELY brittle and crumbled like a stale cookie The nut is "lost" inside the head and I can mostly fish it out using a hook tool I have.

: 20211117_085138.jpg (1.92 MiB) Viewed 1363 times

What has me concerned is that material around the nut appears to be mostly fiber with little to no resin. It crumbles away at the slightest touch.

First: How do I stabalize that? Keep cutting/grinding it away until I hit solid material?

: 20211117_085102.jpg (1.73 MiB) Viewed 1363 times

Second: How would I go about building up a structure to support the nut? Or some other means of mounting the head back on the doll.

: 20211117_085054.jpg (2.04 MiB) Viewed 1363 times

A replacement is on order so this one is for experimental use. If we can't figure out a way to salvage it, I'll mount it on the Roobma and shove some laser pointers in the eye-holes.

seagull · Post by **seagull** » Fri Nov 19, 2021 3:51 am

Clean the crud from around the hole until it starts to feel solid
Punch a big enough hole in a tin lid to take a bolt that secures the head nut underneath
Fill the damaged area with Two part epoxy
Place the head nut into the epoxy repair and wait for it to cure

The bolt can be screwed out and the lid removed

I have assumed you are familiar with epoxy repairs

msasdfjkl · Post by **msasdfjkl** » Fri Nov 19, 2021 10:39 pm

I can't tell from the picture if it is fiber glass. You may want to watch some surfboard repair videos. I use to fix my boards. Just be carefull with the resin it'll get you high as fk.

elarring · Post by **elarring** » Sat Feb 05, 2022 9:51 pm

I had a similar thing happen. The tough part is finding a way to bond the two different materials. There is great metal bonding, but, not certain what the material of the head is actually made of, it's a tough fix, without being able to take the head apart.

RevJack · Post by **RevJack** » Mon Feb 07, 2022 1:00 pm

I have a similar head being sent to me for repairs. Here are my thoughts.
If the material is crumbly, you will want to reinforce it, Attaching to the crumbling material would be a temporary solution. I would reinforce it from the inside as much as possible. This should not be too difficult as long a you have access to a thin resin, epoxy, or polyurethane. My approach would be to place the whole kit together from the outside, help together with duct tape. this is to ensure that the surface is a) sealed and b) flat. You will also need to coat an M16 head bolt in petroleum jelly, (stupidly thick) ans screw it into the bolt. This will coat the bolt and threads. Now mix your Resin/epoxy/poly and inject it inside the head so that it creates a 1/4 inch thick layer. The Petroleum jelly will protect the bolt and inner threads from the resin/epox/poly.

You should wind up with a 1/4 inch thick coating of Resin/epox/poly inside the skull that also fills in the area around the nut, holding it in place and distributing the torsional forces across the entire inner floor of the skull.

Rev Jack.

elarring · Post by **elarring** » Wed Feb 09, 2022 7:07 pm

RevJack wrote:I have a similar head being sent to me for repairs. Here are my thoughts.
If the material is crumbly, you will want to reinforce it, Attaching to the crumbling material would be a temporary solution. I would reinforce it from the inside as much as possible. This should not be too difficult as long a you have access to a thin resin, epoxy, or polyurethane. My approach would be to place the whole kit together from the outside, help together with duct tape. this is to ensure that the surface is a) sealed and b) flat. You will also need to coat an M16 head bolt in petroleum jelly, (stupidly thick) ans screw it into the bolt. This will coat the bolt and threads. Now mix your Resin/epoxy/poly and inject it inside the head so that it creates a 1/4 inch thick layer. The Petroleum jelly will protect the bolt and inner threads from the resin/epox/poly.

You should wind up with a 1/4 inch thick coating of Resin/epox/poly inside the skull that also fills in the area around the nut, holding it in place and distributing the torsional forces across the entire inner floor of the skull.

Rev Jack.

Thank you.

I have a WM head, they all seem to be made out of the same material. What resin or epoxy do you recommend?

The head bolt receiver assembly is still inside the head.

RevJack · Post by **RevJack** » Wed Feb 09, 2022 9:56 pm

I use Smooth-on SmoothCase 300 because I have it lying around. Short ass pot life though, not beginner friendly.
I think I would lean towards Smooth-on EpoxAcast 650 for this application if I was starting from scratch.

elarring · Post by **elarring** » Fri Feb 11, 2022 7:30 pm

RevJack wrote:I use Smooth-on SmoothCase 300 because I have it lying around. Short ass pot life though, not beginner friendly.
I think I would lean towards Smooth-on EpoxAcast 650 for this application if I was starting from scratch.

Thank you

Elektron42 · Post by **Elektron42** » Fri Feb 11, 2022 9:56 pm

RevJack,
I use 3M DP8010, it has about a 2 minute working time and is very pasty, but it does bond to LDPE, unlike most epoxies. Stinks for months….
Will research your suggestions.

elarring · Post by **elarring** » Thu Feb 24, 2022 11:47 am

I pulled out the head bolt assembly, the head is hollow and I plan to fill it with cloth or whatever won't react to the chemicals in the epoxy or hardener, so that the head bolt assembly will stay in place. I grabbed a large flat washer, and nut for the outside.

I'm waiting on the epoxy to show up today and will let you all know how it progresses

RevJack · Post by **RevJack** » Thu Feb 24, 2022 2:24 pm

Excellent. Remember to coat that bolt thickly with vasaline so the epoxy doesn't stick to it!

elarring · Post by **elarring** » Thu Feb 24, 2022 8:59 pm

RevJack wrote:Excellent. Remember to coat that bolt thickly with vasaline so the epoxy doesn't stick to it!

Thanks I did. it took two attempts, but it seems to have worked. Using cloth alone was a mistake, because it slowed the hardening process (I didn't learn this until the second attempt) and on the first try, the cloth let some of the epoxy slip past before it could harden. Though it hardened, and i bought the one hour hardener, I'm going to wait until tomorrow. Initially it looks like it's bonded strong. It's ugly though, lol.

I took precautions not to spill any onto the skin. But, my little shield let some slip. But, it doesn't seem to react to the TPE. One glop, actually had time to harden. I used dish-soap and a natural sponge. A bit of it peeled away. I used baby oil, but the skin seems good so far.

elarring · Post by **elarring** » Wed Mar 02, 2022 8:31 pm

I was finally able to test the repair thoroughly today. It worked, really well. Again, i had to do it twice, because I hadn't anticipated the cloth i used, absorbing the resin and pushing some of the cloth away. If i had to do it again, I would have put more in more cloth and used less absorbent material. I cut an old pillow case with a high thread count and packed it in there tightly. It looks ugly, but it's solid and hard, if not more so, than the original material. It bonded to everything. Thanks again RevJack, I used exactly what you suggested with the 101 hardener.