Think it probably happened when the bodywork was still green and I was doing prep work on it before fitting. I had the body sitting on the workshop floor during that time
Will heating and blocking in position work with GRP?
Any ideas of reshaping a deformed GRP wheel arch. The wheel arch seems to have tightened up so I have lost around 10mm clearance at the back of the
rear wheel. Still have around 12mm clearance but it just looks odd when compared to the other side.
Think it probably happened when the bodywork was still green and I was doing prep work on it before fitting. I had the body sitting on the workshop
floor during that time
Will heating and blocking in position work with GRP?
If you can apply some pressure in the right position while heating up the arch, over a few hours (sometimes days) the distortion will go. I had a
heavy toolbox on my front clip for a month to correct a shut line - it eventually corrected it. When my car is in direct sunlight for a few hours,
everything seems to move 
hmmmmm, I'm sure I parked my car here!!!.................oh wait it's over there, it must have been sunny
Steve
quote:
Originally posted by gottabedone
hmmmmm, I'm sure I parked my car here!!!.................oh wait it's over there, it must have been sunny
Steve
quote:
Originally posted by RazMan
When my car is in direct sunlight for a few hours, everything seems to move
Yep the stuff moves and yep if you can hold it in place and you happen to know a paint shop who would let you chuck it in their oven overnight while
oven is cooling you might be lucky. Worked for me in the past.
Bonnets are the kiddies that move all over the joint and should really be made with high temp resin but nobody does..
Everything has been positioned with blocks and string. Workshop temp has been rasied to 32 with thundering great gas space heaters. Body temp is
around 40-45 with 2 heat-shrink guns and a paint stripper heat gun all targeted on the offending curves. Never nailed heat guns to planks of wood
before, tiz a surreal experience. Snowmen everywhere be affraid
I'm going for 4 hours of this treatment then cooling.
Things will be allowed to cool over the rest of the weekend. Forcast is for +4 overnight this weekend so that should set it. I'll open the
workshop windows tomorrow night and let it cool right down.
Keeping everything crossed!!!
All this just for 10mm....................
I swear that Essex just warmed up a degree!
I hope the plan works
quote:
Originally posted by RazMan
I swear that Essex just warmed up a degree!
The result is good...... ish
Sunday morning the blocks were removed and the gap is 22mm which is just over size
Sunday afternoon the gap had closed up to 18mm which is acceptable but worrying
Sunday evening the gap remained 18mm so I am a little more relaxed 
Bad news 
The rear of the wheel arch now has a couple of small ripples. They are very small and will sand out as they are far less than the
thickness of gel coat. I will add some gel coat before sanding just to make sure I kill them off with one hit. This is not a problem for me as I am
painting the car. But for those using a gel coat finish be aware of this problem
It seems the GRP will flex / expand / contract at different rate to the gel coat. The GRP in this case moved as expected but the gel coat did not want
to, hence ripple.
End result (providing the gap does not change by Monday evening) will be a lot of work to gain 8mm. But the look of the rear end of the car will be
much much better as 2mm is difficult to spot but a 10mm error show up big time.
IMHO 10mm movement is the absolute max that should be attempted using this idea when the part has a gel coat.
Final Update to this bit of work is that the new gap has remained constant even after a couple of days of heating and cooling the workshop. So
I'm going to buff out the ripples and all should be well