MHL Lift Insert Damage with Foothooks - Warning and How to Repair?

[jakemoore]

So I'm using just one front foot hook with my MHL Lift. I've broken the new style foot hooks but with this old style it pulled the insert out of the board. It could be that the board is better off with a single front strap.

Any guru's know how to repair? I cut the pad away so I could see the surface underneath. Does the core take on water and need to dry? Can I just epoxy the insert in? Does it need some glass on top?

[madworld]

Is that Lift board? looks like a custom Gras board.

Yes you need to let it dry out and then get two part marine epoxy and paint the epoxy onto the foam and some q cell or cut some glass into strips and put it in the hole , then paint the insert with epoxy, cram it back in. Try and use as little epoxy as possible so it does not heat up to much when curing and melt the foam.

[jakemoore]

Is that Lift board?

Thanks for the tips. Its a Lift. Do i need glass on top of the insert to hold it down?

[madworld]

Is that Lift board?

Thanks for the tips. Its a Lift. Do i need glass on top of the insert to hold it down?

liftboard.jpg

Well that would help, but you would need to peel off more of the deck pad.

[kostantin]

Greetings,

what I would do if it would be my problem.

Take a small hook and scratch out what I have marked with xxx. This should be foam. You need to go behind what I have marked as ---. The more the better. It will be the ancour of your hook in the future.
But at least one thumb wide 360° around the hole.


Top fiber
----- -------
xxx | hole |xxx <-------foam?
------------------
bottom fibre


Buy cotton flakes. Don't buy milled glas.
Buy glas around 160 to 200m²
Epoxy resin, nothing that starts with 5 Minutes or quick in discreption.

RC modeling shops should store these. The longer the cure period for the epoxy the saver.

Look for something that comes with syringe's. Avoids that you have to find a a libra. Mix the cotton with the epoxy. Fill out the xxx area with epoxy and cotton
Unscrew the hook from the the insert. Sand the insert. Make the hole a little wider to find space for the 2 layers. Take 2 layers of glas, cut the one after the other so you can cover the insert with the glas. Put a litlle epoxy on the insert. Cover it with glas. Put the second layer on the first. Epoxy on the second layer.
Then press the insert with the layers in the hole where the cotton already is.

Let it cure without exposing it to the sun or heat or it will melt your foam core. Once it is cured, cut everything that is higher then your pad with a sharp knife. Put a small piece of plastik foil and drop it on the the repair. Expose this to the sun to finall cure the repair.

You should wake away with 20 bucks for the repair.

tks

Kosta

[jakemoore]

Buy cotton flakes.

I like your thinking Kosta. Why cotton flakes rather than a glass filler like chopped strands or beads?

The core is foam and is visible as the white material in the photo.

Any idea what MHL uses as a core?

[kostantin]

Greetings,


lets see if my english is good enough for further explanations. Every fibre no matter if kevlar, carbon or glass gets a cover during production to prevent the fibre from braking if you bend it. In german it is called "schlichte" This cover is is either made for polyster or epoxy. In 90% chopped glas is made for polyester cover.

Epoxy does not accept fibre with polyester cover. You remain with white parts that did not accept the resin. In this repair case we face a super small area, with a high pull load. Therefore we should do absolute everything to get the best result and cotton flakes are the very best in this case because we don't like to make a big repair out of this.

In any case we need to have a closed part underneath our repair and to use as little resin as possible. Resin never gives strength, but weight. And water will find a way into your foam core. Therefor tripple check if you did every thing to keep it out of your board.

One last word to the schlichte story, the cover has a live time. After 2-3 years the cover gets old. The epoxy stops to stick very good, and the fibre gets difficult to lay in a mold.

tks

Kosta

[kostantin]

Instead of cotton you can also use this. Smallest amount I found. Does allmost the same.

https://www.amazon.com/Phenolic-Micro-B ... roballoons

[TomW]

There's a huge risk you will cause exothermic ( heat) and melt the Eps foam. Eps sucks, I hate it.
Sucks water, doesn't take any exothermic, too soft.
Kosta's approach might work.

I would remove pad 100mm around. Route out the glass and foam about 10mm bigger than insert, glue in HD foam to fill hole, route out for insert, glue in with epoxy and fumed silica, grind flush and put 3 layers of glass over it. Drill out holes for that insert and put pad patch back on.

People don't realise how much work it is to fix these things.

[TomW]

Get a slingshot foothook that flexes.